Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Implement CPU time clocks for the POSIX clock interface. |
| 3 | */ |
| 4 | |
| 5 | #include <linux/sched.h> |
| 6 | #include <linux/posix-timers.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | #include <linux/errno.h> |
Roman Zippel | f8bd225 | 2008-05-01 04:34:31 -0700 | [diff] [blame] | 8 | #include <linux/math64.h> |
| 9 | #include <asm/uaccess.h> |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 10 | #include <linux/kernel_stat.h> |
Xiao Guangrong | 3f0a525 | 2009-08-10 10:52:30 +0800 | [diff] [blame] | 11 | #include <trace/events/timer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 13 | /* |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 14 | * Called after updating RLIMIT_CPU to run cpu timer and update |
| 15 | * tsk->signal->cputime_expires expiration cache if necessary. Needs |
| 16 | * siglock protection since other code may update expiration cache as |
| 17 | * well. |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 18 | */ |
| 19 | void update_rlimit_cpu(unsigned long rlim_new) |
| 20 | { |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 21 | cputime_t cputime = secs_to_cputime(rlim_new); |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 22 | |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 23 | spin_lock_irq(¤t->sighand->siglock); |
| 24 | set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); |
| 25 | spin_unlock_irq(¤t->sighand->siglock); |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 26 | } |
| 27 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 28 | static int check_clock(const clockid_t which_clock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | { |
| 30 | int error = 0; |
| 31 | struct task_struct *p; |
| 32 | const pid_t pid = CPUCLOCK_PID(which_clock); |
| 33 | |
| 34 | if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX) |
| 35 | return -EINVAL; |
| 36 | |
| 37 | if (pid == 0) |
| 38 | return 0; |
| 39 | |
| 40 | read_lock(&tasklist_lock); |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 41 | p = find_task_by_vpid(pid); |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 42 | if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ? |
| 43 | same_thread_group(p, current) : thread_group_leader(p))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | error = -EINVAL; |
| 45 | } |
| 46 | read_unlock(&tasklist_lock); |
| 47 | |
| 48 | return error; |
| 49 | } |
| 50 | |
| 51 | static inline union cpu_time_count |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 52 | timespec_to_sample(const clockid_t which_clock, const struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | { |
| 54 | union cpu_time_count ret; |
| 55 | ret.sched = 0; /* high half always zero when .cpu used */ |
| 56 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
Oleg Nesterov | ee500f2 | 2005-11-28 13:43:55 -0800 | [diff] [blame] | 57 | ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | } else { |
| 59 | ret.cpu = timespec_to_cputime(tp); |
| 60 | } |
| 61 | return ret; |
| 62 | } |
| 63 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 64 | static void sample_to_timespec(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | union cpu_time_count cpu, |
| 66 | struct timespec *tp) |
| 67 | { |
Roman Zippel | f8bd225 | 2008-05-01 04:34:31 -0700 | [diff] [blame] | 68 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) |
| 69 | *tp = ns_to_timespec(cpu.sched); |
| 70 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | cputime_to_timespec(cpu.cpu, tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | } |
| 73 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 74 | static inline int cpu_time_before(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | union cpu_time_count now, |
| 76 | union cpu_time_count then) |
| 77 | { |
| 78 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
| 79 | return now.sched < then.sched; |
| 80 | } else { |
| 81 | return cputime_lt(now.cpu, then.cpu); |
| 82 | } |
| 83 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 84 | static inline void cpu_time_add(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | union cpu_time_count *acc, |
| 86 | union cpu_time_count val) |
| 87 | { |
| 88 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
| 89 | acc->sched += val.sched; |
| 90 | } else { |
| 91 | acc->cpu = cputime_add(acc->cpu, val.cpu); |
| 92 | } |
| 93 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 94 | static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | union cpu_time_count a, |
| 96 | union cpu_time_count b) |
| 97 | { |
| 98 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
| 99 | a.sched -= b.sched; |
| 100 | } else { |
| 101 | a.cpu = cputime_sub(a.cpu, b.cpu); |
| 102 | } |
| 103 | return a; |
| 104 | } |
| 105 | |
| 106 | /* |
Thomas Gleixner | ac08c26 | 2006-10-17 00:09:39 -0700 | [diff] [blame] | 107 | * Divide and limit the result to res >= 1 |
| 108 | * |
| 109 | * This is necessary to prevent signal delivery starvation, when the result of |
| 110 | * the division would be rounded down to 0. |
| 111 | */ |
| 112 | static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div) |
| 113 | { |
| 114 | cputime_t res = cputime_div(time, div); |
| 115 | |
| 116 | return max_t(cputime_t, res, 1); |
| 117 | } |
| 118 | |
| 119 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | * Update expiry time from increment, and increase overrun count, |
| 121 | * given the current clock sample. |
| 122 | */ |
Oleg Nesterov | 7a4ed93 | 2005-10-26 20:26:53 +0400 | [diff] [blame] | 123 | static void bump_cpu_timer(struct k_itimer *timer, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | union cpu_time_count now) |
| 125 | { |
| 126 | int i; |
| 127 | |
| 128 | if (timer->it.cpu.incr.sched == 0) |
| 129 | return; |
| 130 | |
| 131 | if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) { |
| 132 | unsigned long long delta, incr; |
| 133 | |
| 134 | if (now.sched < timer->it.cpu.expires.sched) |
| 135 | return; |
| 136 | incr = timer->it.cpu.incr.sched; |
| 137 | delta = now.sched + incr - timer->it.cpu.expires.sched; |
| 138 | /* Don't use (incr*2 < delta), incr*2 might overflow. */ |
| 139 | for (i = 0; incr < delta - incr; i++) |
| 140 | incr = incr << 1; |
| 141 | for (; i >= 0; incr >>= 1, i--) { |
Oleg Nesterov | 7a4ed93 | 2005-10-26 20:26:53 +0400 | [diff] [blame] | 142 | if (delta < incr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | continue; |
| 144 | timer->it.cpu.expires.sched += incr; |
| 145 | timer->it_overrun += 1 << i; |
| 146 | delta -= incr; |
| 147 | } |
| 148 | } else { |
| 149 | cputime_t delta, incr; |
| 150 | |
| 151 | if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu)) |
| 152 | return; |
| 153 | incr = timer->it.cpu.incr.cpu; |
| 154 | delta = cputime_sub(cputime_add(now.cpu, incr), |
| 155 | timer->it.cpu.expires.cpu); |
| 156 | /* Don't use (incr*2 < delta), incr*2 might overflow. */ |
| 157 | for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++) |
| 158 | incr = cputime_add(incr, incr); |
| 159 | for (; i >= 0; incr = cputime_halve(incr), i--) { |
Oleg Nesterov | 7a4ed93 | 2005-10-26 20:26:53 +0400 | [diff] [blame] | 160 | if (cputime_lt(delta, incr)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | continue; |
| 162 | timer->it.cpu.expires.cpu = |
| 163 | cputime_add(timer->it.cpu.expires.cpu, incr); |
| 164 | timer->it_overrun += 1 << i; |
| 165 | delta = cputime_sub(delta, incr); |
| 166 | } |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | static inline cputime_t prof_ticks(struct task_struct *p) |
| 171 | { |
| 172 | return cputime_add(p->utime, p->stime); |
| 173 | } |
| 174 | static inline cputime_t virt_ticks(struct task_struct *p) |
| 175 | { |
| 176 | return p->utime; |
| 177 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 179 | int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | { |
| 181 | int error = check_clock(which_clock); |
| 182 | if (!error) { |
| 183 | tp->tv_sec = 0; |
| 184 | tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ); |
| 185 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
| 186 | /* |
| 187 | * If sched_clock is using a cycle counter, we |
| 188 | * don't have any idea of its true resolution |
| 189 | * exported, but it is much more than 1s/HZ. |
| 190 | */ |
| 191 | tp->tv_nsec = 1; |
| 192 | } |
| 193 | } |
| 194 | return error; |
| 195 | } |
| 196 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 197 | int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
| 199 | /* |
| 200 | * You can never reset a CPU clock, but we check for other errors |
| 201 | * in the call before failing with EPERM. |
| 202 | */ |
| 203 | int error = check_clock(which_clock); |
| 204 | if (error == 0) { |
| 205 | error = -EPERM; |
| 206 | } |
| 207 | return error; |
| 208 | } |
| 209 | |
| 210 | |
| 211 | /* |
| 212 | * Sample a per-thread clock for the given task. |
| 213 | */ |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 214 | static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | union cpu_time_count *cpu) |
| 216 | { |
| 217 | switch (CPUCLOCK_WHICH(which_clock)) { |
| 218 | default: |
| 219 | return -EINVAL; |
| 220 | case CPUCLOCK_PROF: |
| 221 | cpu->cpu = prof_ticks(p); |
| 222 | break; |
| 223 | case CPUCLOCK_VIRT: |
| 224 | cpu->cpu = virt_ticks(p); |
| 225 | break; |
| 226 | case CPUCLOCK_SCHED: |
Hidetoshi Seto | c5f8d99 | 2009-03-31 16:56:03 +0900 | [diff] [blame] | 227 | cpu->sched = task_sched_runtime(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | break; |
| 229 | } |
| 230 | return 0; |
| 231 | } |
| 232 | |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 233 | void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) |
| 234 | { |
| 235 | struct sighand_struct *sighand; |
| 236 | struct signal_struct *sig; |
| 237 | struct task_struct *t; |
| 238 | |
| 239 | *times = INIT_CPUTIME; |
| 240 | |
| 241 | rcu_read_lock(); |
| 242 | sighand = rcu_dereference(tsk->sighand); |
| 243 | if (!sighand) |
| 244 | goto out; |
| 245 | |
| 246 | sig = tsk->signal; |
| 247 | |
| 248 | t = tsk; |
| 249 | do { |
| 250 | times->utime = cputime_add(times->utime, t->utime); |
| 251 | times->stime = cputime_add(times->stime, t->stime); |
| 252 | times->sum_exec_runtime += t->se.sum_exec_runtime; |
| 253 | |
| 254 | t = next_thread(t); |
| 255 | } while (t != tsk); |
| 256 | |
| 257 | times->utime = cputime_add(times->utime, sig->utime); |
| 258 | times->stime = cputime_add(times->stime, sig->stime); |
| 259 | times->sum_exec_runtime += sig->sum_sched_runtime; |
| 260 | out: |
| 261 | rcu_read_unlock(); |
| 262 | } |
| 263 | |
Peter Zijlstra | 4da94d49 | 2009-02-11 11:30:27 +0100 | [diff] [blame] | 264 | static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b) |
| 265 | { |
| 266 | if (cputime_gt(b->utime, a->utime)) |
| 267 | a->utime = b->utime; |
| 268 | |
| 269 | if (cputime_gt(b->stime, a->stime)) |
| 270 | a->stime = b->stime; |
| 271 | |
| 272 | if (b->sum_exec_runtime > a->sum_exec_runtime) |
| 273 | a->sum_exec_runtime = b->sum_exec_runtime; |
| 274 | } |
| 275 | |
| 276 | void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) |
| 277 | { |
| 278 | struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; |
| 279 | struct task_cputime sum; |
| 280 | unsigned long flags; |
| 281 | |
| 282 | spin_lock_irqsave(&cputimer->lock, flags); |
| 283 | if (!cputimer->running) { |
| 284 | cputimer->running = 1; |
| 285 | /* |
| 286 | * The POSIX timer interface allows for absolute time expiry |
| 287 | * values through the TIMER_ABSTIME flag, therefore we have |
| 288 | * to synchronize the timer to the clock every time we start |
| 289 | * it. |
| 290 | */ |
| 291 | thread_group_cputime(tsk, &sum); |
| 292 | update_gt_cputime(&cputimer->cputime, &sum); |
| 293 | } |
| 294 | *times = cputimer->cputime; |
| 295 | spin_unlock_irqrestore(&cputimer->lock, flags); |
| 296 | } |
| 297 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | /* |
| 299 | * Sample a process (thread group) clock for the given group_leader task. |
| 300 | * Must be called with tasklist_lock held for reading. |
| 301 | */ |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 302 | static int cpu_clock_sample_group(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | struct task_struct *p, |
| 304 | union cpu_time_count *cpu) |
| 305 | { |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 306 | struct task_cputime cputime; |
| 307 | |
Petr Tesarik | eccdaea | 2008-11-24 15:46:31 +0100 | [diff] [blame] | 308 | switch (CPUCLOCK_WHICH(which_clock)) { |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 309 | default: |
| 310 | return -EINVAL; |
| 311 | case CPUCLOCK_PROF: |
Hidetoshi Seto | c5f8d99 | 2009-03-31 16:56:03 +0900 | [diff] [blame] | 312 | thread_group_cputime(p, &cputime); |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 313 | cpu->cpu = cputime_add(cputime.utime, cputime.stime); |
| 314 | break; |
| 315 | case CPUCLOCK_VIRT: |
Hidetoshi Seto | c5f8d99 | 2009-03-31 16:56:03 +0900 | [diff] [blame] | 316 | thread_group_cputime(p, &cputime); |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 317 | cpu->cpu = cputime.utime; |
| 318 | break; |
| 319 | case CPUCLOCK_SCHED: |
Hidetoshi Seto | c5f8d99 | 2009-03-31 16:56:03 +0900 | [diff] [blame] | 320 | cpu->sched = thread_group_sched_runtime(p); |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 321 | break; |
| 322 | } |
| 323 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 324 | } |
| 325 | |
| 326 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 327 | int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | { |
| 329 | const pid_t pid = CPUCLOCK_PID(which_clock); |
| 330 | int error = -EINVAL; |
| 331 | union cpu_time_count rtn; |
| 332 | |
| 333 | if (pid == 0) { |
| 334 | /* |
| 335 | * Special case constant value for our own clocks. |
| 336 | * We don't have to do any lookup to find ourselves. |
| 337 | */ |
| 338 | if (CPUCLOCK_PERTHREAD(which_clock)) { |
| 339 | /* |
| 340 | * Sampling just ourselves we can do with no locking. |
| 341 | */ |
| 342 | error = cpu_clock_sample(which_clock, |
| 343 | current, &rtn); |
| 344 | } else { |
| 345 | read_lock(&tasklist_lock); |
| 346 | error = cpu_clock_sample_group(which_clock, |
| 347 | current, &rtn); |
| 348 | read_unlock(&tasklist_lock); |
| 349 | } |
| 350 | } else { |
| 351 | /* |
| 352 | * Find the given PID, and validate that the caller |
| 353 | * should be able to see it. |
| 354 | */ |
| 355 | struct task_struct *p; |
Paul E. McKenney | 1f2ea08 | 2007-02-16 01:28:22 -0800 | [diff] [blame] | 356 | rcu_read_lock(); |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 357 | p = find_task_by_vpid(pid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | if (p) { |
| 359 | if (CPUCLOCK_PERTHREAD(which_clock)) { |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 360 | if (same_thread_group(p, current)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | error = cpu_clock_sample(which_clock, |
| 362 | p, &rtn); |
| 363 | } |
Paul E. McKenney | 1f2ea08 | 2007-02-16 01:28:22 -0800 | [diff] [blame] | 364 | } else { |
| 365 | read_lock(&tasklist_lock); |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 366 | if (thread_group_leader(p) && p->signal) { |
Paul E. McKenney | 1f2ea08 | 2007-02-16 01:28:22 -0800 | [diff] [blame] | 367 | error = |
| 368 | cpu_clock_sample_group(which_clock, |
| 369 | p, &rtn); |
| 370 | } |
| 371 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | } |
| 373 | } |
Paul E. McKenney | 1f2ea08 | 2007-02-16 01:28:22 -0800 | [diff] [blame] | 374 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | } |
| 376 | |
| 377 | if (error) |
| 378 | return error; |
| 379 | sample_to_timespec(which_clock, rtn, tp); |
| 380 | return 0; |
| 381 | } |
| 382 | |
| 383 | |
| 384 | /* |
| 385 | * Validate the clockid_t for a new CPU-clock timer, and initialize the timer. |
Stanislaw Gruszka | ba5ea95 | 2009-11-17 14:14:13 -0800 | [diff] [blame] | 386 | * This is called from sys_timer_create() and do_cpu_nanosleep() with the |
| 387 | * new timer already all-zeros initialized. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | */ |
| 389 | int posix_cpu_timer_create(struct k_itimer *new_timer) |
| 390 | { |
| 391 | int ret = 0; |
| 392 | const pid_t pid = CPUCLOCK_PID(new_timer->it_clock); |
| 393 | struct task_struct *p; |
| 394 | |
| 395 | if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX) |
| 396 | return -EINVAL; |
| 397 | |
| 398 | INIT_LIST_HEAD(&new_timer->it.cpu.entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | |
| 400 | read_lock(&tasklist_lock); |
| 401 | if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) { |
| 402 | if (pid == 0) { |
| 403 | p = current; |
| 404 | } else { |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 405 | p = find_task_by_vpid(pid); |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 406 | if (p && !same_thread_group(p, current)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | p = NULL; |
| 408 | } |
| 409 | } else { |
| 410 | if (pid == 0) { |
| 411 | p = current->group_leader; |
| 412 | } else { |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 413 | p = find_task_by_vpid(pid); |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 414 | if (p && !thread_group_leader(p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | p = NULL; |
| 416 | } |
| 417 | } |
| 418 | new_timer->it.cpu.task = p; |
| 419 | if (p) { |
| 420 | get_task_struct(p); |
| 421 | } else { |
| 422 | ret = -EINVAL; |
| 423 | } |
| 424 | read_unlock(&tasklist_lock); |
| 425 | |
| 426 | return ret; |
| 427 | } |
| 428 | |
| 429 | /* |
| 430 | * Clean up a CPU-clock timer that is about to be destroyed. |
| 431 | * This is called from timer deletion with the timer already locked. |
| 432 | * If we return TIMER_RETRY, it's necessary to release the timer's lock |
| 433 | * and try again. (This happens when the timer is in the middle of firing.) |
| 434 | */ |
| 435 | int posix_cpu_timer_del(struct k_itimer *timer) |
| 436 | { |
| 437 | struct task_struct *p = timer->it.cpu.task; |
Oleg Nesterov | 108150e | 2005-10-23 20:25:39 +0400 | [diff] [blame] | 438 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | |
Oleg Nesterov | 108150e | 2005-10-23 20:25:39 +0400 | [diff] [blame] | 440 | if (likely(p != NULL)) { |
Linus Torvalds | 9465bee | 2005-10-21 15:36:00 -0700 | [diff] [blame] | 441 | read_lock(&tasklist_lock); |
| 442 | if (unlikely(p->signal == NULL)) { |
| 443 | /* |
| 444 | * We raced with the reaping of the task. |
| 445 | * The deletion should have cleared us off the list. |
| 446 | */ |
| 447 | BUG_ON(!list_empty(&timer->it.cpu.entry)); |
| 448 | } else { |
Linus Torvalds | 9465bee | 2005-10-21 15:36:00 -0700 | [diff] [blame] | 449 | spin_lock(&p->sighand->siglock); |
Oleg Nesterov | 108150e | 2005-10-23 20:25:39 +0400 | [diff] [blame] | 450 | if (timer->it.cpu.firing) |
| 451 | ret = TIMER_RETRY; |
| 452 | else |
| 453 | list_del(&timer->it.cpu.entry); |
Linus Torvalds | 9465bee | 2005-10-21 15:36:00 -0700 | [diff] [blame] | 454 | spin_unlock(&p->sighand->siglock); |
| 455 | } |
| 456 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | |
Oleg Nesterov | 108150e | 2005-10-23 20:25:39 +0400 | [diff] [blame] | 458 | if (!ret) |
| 459 | put_task_struct(p); |
| 460 | } |
| 461 | |
| 462 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | } |
| 464 | |
| 465 | /* |
| 466 | * Clean out CPU timers still ticking when a thread exited. The task |
| 467 | * pointer is cleared, and the expiry time is replaced with the residual |
| 468 | * time for later timer_gettime calls to return. |
| 469 | * This must be called with the siglock held. |
| 470 | */ |
| 471 | static void cleanup_timers(struct list_head *head, |
| 472 | cputime_t utime, cputime_t stime, |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 473 | unsigned long long sum_exec_runtime) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | { |
| 475 | struct cpu_timer_list *timer, *next; |
| 476 | cputime_t ptime = cputime_add(utime, stime); |
| 477 | |
| 478 | list_for_each_entry_safe(timer, next, head, entry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | list_del_init(&timer->entry); |
| 480 | if (cputime_lt(timer->expires.cpu, ptime)) { |
| 481 | timer->expires.cpu = cputime_zero; |
| 482 | } else { |
| 483 | timer->expires.cpu = cputime_sub(timer->expires.cpu, |
| 484 | ptime); |
| 485 | } |
| 486 | } |
| 487 | |
| 488 | ++head; |
| 489 | list_for_each_entry_safe(timer, next, head, entry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | list_del_init(&timer->entry); |
| 491 | if (cputime_lt(timer->expires.cpu, utime)) { |
| 492 | timer->expires.cpu = cputime_zero; |
| 493 | } else { |
| 494 | timer->expires.cpu = cputime_sub(timer->expires.cpu, |
| 495 | utime); |
| 496 | } |
| 497 | } |
| 498 | |
| 499 | ++head; |
| 500 | list_for_each_entry_safe(timer, next, head, entry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | list_del_init(&timer->entry); |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 502 | if (timer->expires.sched < sum_exec_runtime) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | timer->expires.sched = 0; |
| 504 | } else { |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 505 | timer->expires.sched -= sum_exec_runtime; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | } |
| 507 | } |
| 508 | } |
| 509 | |
| 510 | /* |
| 511 | * These are both called with the siglock held, when the current thread |
| 512 | * is being reaped. When the final (leader) thread in the group is reaped, |
| 513 | * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit. |
| 514 | */ |
| 515 | void posix_cpu_timers_exit(struct task_struct *tsk) |
| 516 | { |
| 517 | cleanup_timers(tsk->cpu_timers, |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 518 | tsk->utime, tsk->stime, tsk->se.sum_exec_runtime); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | |
| 520 | } |
| 521 | void posix_cpu_timers_exit_group(struct task_struct *tsk) |
| 522 | { |
Stanislaw Gruszka | 17d42c1 | 2009-08-06 16:03:30 -0700 | [diff] [blame] | 523 | struct signal_struct *const sig = tsk->signal; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 524 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | cleanup_timers(tsk->signal->cpu_timers, |
Stanislaw Gruszka | 17d42c1 | 2009-08-06 16:03:30 -0700 | [diff] [blame] | 526 | cputime_add(tsk->utime, sig->utime), |
| 527 | cputime_add(tsk->stime, sig->stime), |
| 528 | tsk->se.sum_exec_runtime + sig->sum_sched_runtime); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | } |
| 530 | |
| 531 | static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now) |
| 532 | { |
| 533 | /* |
| 534 | * That's all for this thread or process. |
| 535 | * We leave our residual in expires to be reported. |
| 536 | */ |
| 537 | put_task_struct(timer->it.cpu.task); |
| 538 | timer->it.cpu.task = NULL; |
| 539 | timer->it.cpu.expires = cpu_time_sub(timer->it_clock, |
| 540 | timer->it.cpu.expires, |
| 541 | now); |
| 542 | } |
| 543 | |
Stanislaw Gruszka | d1e3b6d | 2009-07-29 12:15:28 +0200 | [diff] [blame] | 544 | static inline int expires_gt(cputime_t expires, cputime_t new_exp) |
| 545 | { |
| 546 | return cputime_eq(expires, cputime_zero) || |
| 547 | cputime_gt(expires, new_exp); |
| 548 | } |
| 549 | |
| 550 | static inline int expires_le(cputime_t expires, cputime_t new_exp) |
| 551 | { |
| 552 | return !cputime_eq(expires, cputime_zero) && |
| 553 | cputime_le(expires, new_exp); |
| 554 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | /* |
| 556 | * Insert the timer on the appropriate list before any timers that |
| 557 | * expire later. This must be called with the tasklist_lock held |
| 558 | * for reading, and interrupts disabled. |
| 559 | */ |
| 560 | static void arm_timer(struct k_itimer *timer, union cpu_time_count now) |
| 561 | { |
| 562 | struct task_struct *p = timer->it.cpu.task; |
| 563 | struct list_head *head, *listpos; |
| 564 | struct cpu_timer_list *const nt = &timer->it.cpu; |
| 565 | struct cpu_timer_list *next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | |
| 567 | head = (CPUCLOCK_PERTHREAD(timer->it_clock) ? |
| 568 | p->cpu_timers : p->signal->cpu_timers); |
| 569 | head += CPUCLOCK_WHICH(timer->it_clock); |
| 570 | |
| 571 | BUG_ON(!irqs_disabled()); |
| 572 | spin_lock(&p->sighand->siglock); |
| 573 | |
| 574 | listpos = head; |
| 575 | if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) { |
| 576 | list_for_each_entry(next, head, entry) { |
Linus Torvalds | 70ab81c | 2005-10-26 11:23:06 -0700 | [diff] [blame] | 577 | if (next->expires.sched > nt->expires.sched) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | break; |
Linus Torvalds | 70ab81c | 2005-10-26 11:23:06 -0700 | [diff] [blame] | 579 | listpos = &next->entry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | } |
| 581 | } else { |
| 582 | list_for_each_entry(next, head, entry) { |
Linus Torvalds | 70ab81c | 2005-10-26 11:23:06 -0700 | [diff] [blame] | 583 | if (cputime_gt(next->expires.cpu, nt->expires.cpu)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | break; |
Linus Torvalds | 70ab81c | 2005-10-26 11:23:06 -0700 | [diff] [blame] | 585 | listpos = &next->entry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | } |
| 587 | } |
| 588 | list_add(&nt->entry, listpos); |
| 589 | |
| 590 | if (listpos == head) { |
| 591 | /* |
| 592 | * We are the new earliest-expiring timer. |
| 593 | * If we are a thread timer, there can always |
| 594 | * be a process timer telling us to stop earlier. |
| 595 | */ |
| 596 | |
| 597 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
Stanislaw Gruszka | d1e3b6d | 2009-07-29 12:15:28 +0200 | [diff] [blame] | 598 | union cpu_time_count *exp = &nt->expires; |
| 599 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | switch (CPUCLOCK_WHICH(timer->it_clock)) { |
| 601 | default: |
| 602 | BUG(); |
| 603 | case CPUCLOCK_PROF: |
Stanislaw Gruszka | d1e3b6d | 2009-07-29 12:15:28 +0200 | [diff] [blame] | 604 | if (expires_gt(p->cputime_expires.prof_exp, |
| 605 | exp->cpu)) |
| 606 | p->cputime_expires.prof_exp = exp->cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | break; |
| 608 | case CPUCLOCK_VIRT: |
Stanislaw Gruszka | d1e3b6d | 2009-07-29 12:15:28 +0200 | [diff] [blame] | 609 | if (expires_gt(p->cputime_expires.virt_exp, |
| 610 | exp->cpu)) |
| 611 | p->cputime_expires.virt_exp = exp->cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | break; |
| 613 | case CPUCLOCK_SCHED: |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 614 | if (p->cputime_expires.sched_exp == 0 || |
Stanislaw Gruszka | d1e3b6d | 2009-07-29 12:15:28 +0200 | [diff] [blame] | 615 | p->cputime_expires.sched_exp > exp->sched) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 616 | p->cputime_expires.sched_exp = |
Stanislaw Gruszka | d1e3b6d | 2009-07-29 12:15:28 +0200 | [diff] [blame] | 617 | exp->sched; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 618 | break; |
| 619 | } |
| 620 | } else { |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 621 | struct signal_struct *const sig = p->signal; |
| 622 | union cpu_time_count *exp = &timer->it.cpu.expires; |
| 623 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | /* |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 625 | * For a process timer, set the cached expiration time. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | */ |
| 627 | switch (CPUCLOCK_WHICH(timer->it_clock)) { |
| 628 | default: |
| 629 | BUG(); |
| 630 | case CPUCLOCK_VIRT: |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 631 | if (expires_gt(sig->cputime_expires.virt_exp, exp->cpu)) |
| 632 | sig->cputime_expires.virt_exp = exp->cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | case CPUCLOCK_PROF: |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 634 | if (expires_gt(sig->cputime_expires.prof_exp, exp->cpu)) |
| 635 | sig->cputime_expires.prof_exp = exp->cpu; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 636 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | case CPUCLOCK_SCHED: |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 638 | sig->cputime_expires.sched_exp = exp->sched; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | break; |
| 640 | } |
| 641 | } |
| 642 | } |
| 643 | |
| 644 | spin_unlock(&p->sighand->siglock); |
| 645 | } |
| 646 | |
| 647 | /* |
| 648 | * The timer is locked, fire it and arrange for its reload. |
| 649 | */ |
| 650 | static void cpu_timer_fire(struct k_itimer *timer) |
| 651 | { |
| 652 | if (unlikely(timer->sigq == NULL)) { |
| 653 | /* |
| 654 | * This a special case for clock_nanosleep, |
| 655 | * not a normal timer from sys_timer_create. |
| 656 | */ |
| 657 | wake_up_process(timer->it_process); |
| 658 | timer->it.cpu.expires.sched = 0; |
| 659 | } else if (timer->it.cpu.incr.sched == 0) { |
| 660 | /* |
| 661 | * One-shot timer. Clear it as soon as it's fired. |
| 662 | */ |
| 663 | posix_timer_event(timer, 0); |
| 664 | timer->it.cpu.expires.sched = 0; |
| 665 | } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) { |
| 666 | /* |
| 667 | * The signal did not get queued because the signal |
| 668 | * was ignored, so we won't get any callback to |
| 669 | * reload the timer. But we need to keep it |
| 670 | * ticking in case the signal is deliverable next time. |
| 671 | */ |
| 672 | posix_cpu_timer_schedule(timer); |
| 673 | } |
| 674 | } |
| 675 | |
| 676 | /* |
Peter Zijlstra | 3997ad3 | 2009-02-12 15:00:52 +0100 | [diff] [blame] | 677 | * Sample a process (thread group) timer for the given group_leader task. |
| 678 | * Must be called with tasklist_lock held for reading. |
| 679 | */ |
| 680 | static int cpu_timer_sample_group(const clockid_t which_clock, |
| 681 | struct task_struct *p, |
| 682 | union cpu_time_count *cpu) |
| 683 | { |
| 684 | struct task_cputime cputime; |
| 685 | |
| 686 | thread_group_cputimer(p, &cputime); |
| 687 | switch (CPUCLOCK_WHICH(which_clock)) { |
| 688 | default: |
| 689 | return -EINVAL; |
| 690 | case CPUCLOCK_PROF: |
| 691 | cpu->cpu = cputime_add(cputime.utime, cputime.stime); |
| 692 | break; |
| 693 | case CPUCLOCK_VIRT: |
| 694 | cpu->cpu = cputime.utime; |
| 695 | break; |
| 696 | case CPUCLOCK_SCHED: |
| 697 | cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p); |
| 698 | break; |
| 699 | } |
| 700 | return 0; |
| 701 | } |
| 702 | |
| 703 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | * Guts of sys_timer_settime for CPU timers. |
| 705 | * This is called with the timer locked and interrupts disabled. |
| 706 | * If we return TIMER_RETRY, it's necessary to release the timer's lock |
| 707 | * and try again. (This happens when the timer is in the middle of firing.) |
| 708 | */ |
| 709 | int posix_cpu_timer_set(struct k_itimer *timer, int flags, |
| 710 | struct itimerspec *new, struct itimerspec *old) |
| 711 | { |
| 712 | struct task_struct *p = timer->it.cpu.task; |
| 713 | union cpu_time_count old_expires, new_expires, val; |
| 714 | int ret; |
| 715 | |
| 716 | if (unlikely(p == NULL)) { |
| 717 | /* |
| 718 | * Timer refers to a dead task's clock. |
| 719 | */ |
| 720 | return -ESRCH; |
| 721 | } |
| 722 | |
| 723 | new_expires = timespec_to_sample(timer->it_clock, &new->it_value); |
| 724 | |
| 725 | read_lock(&tasklist_lock); |
| 726 | /* |
| 727 | * We need the tasklist_lock to protect against reaping that |
| 728 | * clears p->signal. If p has just been reaped, we can no |
| 729 | * longer get any information about it at all. |
| 730 | */ |
| 731 | if (unlikely(p->signal == NULL)) { |
| 732 | read_unlock(&tasklist_lock); |
| 733 | put_task_struct(p); |
| 734 | timer->it.cpu.task = NULL; |
| 735 | return -ESRCH; |
| 736 | } |
| 737 | |
| 738 | /* |
| 739 | * Disarm any old timer after extracting its expiry time. |
| 740 | */ |
| 741 | BUG_ON(!irqs_disabled()); |
Oleg Nesterov | a69ac4a | 2005-10-24 18:29:58 +0400 | [diff] [blame] | 742 | |
| 743 | ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | spin_lock(&p->sighand->siglock); |
| 745 | old_expires = timer->it.cpu.expires; |
Oleg Nesterov | a69ac4a | 2005-10-24 18:29:58 +0400 | [diff] [blame] | 746 | if (unlikely(timer->it.cpu.firing)) { |
| 747 | timer->it.cpu.firing = -1; |
| 748 | ret = TIMER_RETRY; |
| 749 | } else |
| 750 | list_del_init(&timer->it.cpu.entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | spin_unlock(&p->sighand->siglock); |
| 752 | |
| 753 | /* |
| 754 | * We need to sample the current value to convert the new |
| 755 | * value from to relative and absolute, and to convert the |
| 756 | * old value from absolute to relative. To set a process |
| 757 | * timer, we need a sample to balance the thread expiry |
| 758 | * times (in arm_timer). With an absolute time, we must |
| 759 | * check if it's already passed. In short, we need a sample. |
| 760 | */ |
| 761 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
| 762 | cpu_clock_sample(timer->it_clock, p, &val); |
| 763 | } else { |
Peter Zijlstra | 3997ad3 | 2009-02-12 15:00:52 +0100 | [diff] [blame] | 764 | cpu_timer_sample_group(timer->it_clock, p, &val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | } |
| 766 | |
| 767 | if (old) { |
| 768 | if (old_expires.sched == 0) { |
| 769 | old->it_value.tv_sec = 0; |
| 770 | old->it_value.tv_nsec = 0; |
| 771 | } else { |
| 772 | /* |
| 773 | * Update the timer in case it has |
| 774 | * overrun already. If it has, |
| 775 | * we'll report it as having overrun |
| 776 | * and with the next reloaded timer |
| 777 | * already ticking, though we are |
| 778 | * swallowing that pending |
| 779 | * notification here to install the |
| 780 | * new setting. |
| 781 | */ |
| 782 | bump_cpu_timer(timer, val); |
| 783 | if (cpu_time_before(timer->it_clock, val, |
| 784 | timer->it.cpu.expires)) { |
| 785 | old_expires = cpu_time_sub( |
| 786 | timer->it_clock, |
| 787 | timer->it.cpu.expires, val); |
| 788 | sample_to_timespec(timer->it_clock, |
| 789 | old_expires, |
| 790 | &old->it_value); |
| 791 | } else { |
| 792 | old->it_value.tv_nsec = 1; |
| 793 | old->it_value.tv_sec = 0; |
| 794 | } |
| 795 | } |
| 796 | } |
| 797 | |
Oleg Nesterov | a69ac4a | 2005-10-24 18:29:58 +0400 | [diff] [blame] | 798 | if (unlikely(ret)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | /* |
| 800 | * We are colliding with the timer actually firing. |
| 801 | * Punt after filling in the timer's old value, and |
| 802 | * disable this firing since we are already reporting |
| 803 | * it as an overrun (thanks to bump_cpu_timer above). |
| 804 | */ |
| 805 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | goto out; |
| 807 | } |
| 808 | |
| 809 | if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) { |
| 810 | cpu_time_add(timer->it_clock, &new_expires, val); |
| 811 | } |
| 812 | |
| 813 | /* |
| 814 | * Install the new expiry time (or zero). |
| 815 | * For a timer with no notification action, we don't actually |
| 816 | * arm the timer (we'll just fake it for timer_gettime). |
| 817 | */ |
| 818 | timer->it.cpu.expires = new_expires; |
| 819 | if (new_expires.sched != 0 && |
| 820 | (timer->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE && |
| 821 | cpu_time_before(timer->it_clock, val, new_expires)) { |
| 822 | arm_timer(timer, val); |
| 823 | } |
| 824 | |
| 825 | read_unlock(&tasklist_lock); |
| 826 | |
| 827 | /* |
| 828 | * Install the new reload setting, and |
| 829 | * set up the signal and overrun bookkeeping. |
| 830 | */ |
| 831 | timer->it.cpu.incr = timespec_to_sample(timer->it_clock, |
| 832 | &new->it_interval); |
| 833 | |
| 834 | /* |
| 835 | * This acts as a modification timestamp for the timer, |
| 836 | * so any automatic reload attempt will punt on seeing |
| 837 | * that we have reset the timer manually. |
| 838 | */ |
| 839 | timer->it_requeue_pending = (timer->it_requeue_pending + 2) & |
| 840 | ~REQUEUE_PENDING; |
| 841 | timer->it_overrun_last = 0; |
| 842 | timer->it_overrun = -1; |
| 843 | |
| 844 | if (new_expires.sched != 0 && |
| 845 | (timer->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE && |
| 846 | !cpu_time_before(timer->it_clock, val, new_expires)) { |
| 847 | /* |
| 848 | * The designated time already passed, so we notify |
| 849 | * immediately, even if the thread never runs to |
| 850 | * accumulate more time on this clock. |
| 851 | */ |
| 852 | cpu_timer_fire(timer); |
| 853 | } |
| 854 | |
| 855 | ret = 0; |
| 856 | out: |
| 857 | if (old) { |
| 858 | sample_to_timespec(timer->it_clock, |
| 859 | timer->it.cpu.incr, &old->it_interval); |
| 860 | } |
| 861 | return ret; |
| 862 | } |
| 863 | |
| 864 | void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) |
| 865 | { |
| 866 | union cpu_time_count now; |
| 867 | struct task_struct *p = timer->it.cpu.task; |
| 868 | int clear_dead; |
| 869 | |
| 870 | /* |
| 871 | * Easy part: convert the reload time. |
| 872 | */ |
| 873 | sample_to_timespec(timer->it_clock, |
| 874 | timer->it.cpu.incr, &itp->it_interval); |
| 875 | |
| 876 | if (timer->it.cpu.expires.sched == 0) { /* Timer not armed at all. */ |
| 877 | itp->it_value.tv_sec = itp->it_value.tv_nsec = 0; |
| 878 | return; |
| 879 | } |
| 880 | |
| 881 | if (unlikely(p == NULL)) { |
| 882 | /* |
| 883 | * This task already died and the timer will never fire. |
| 884 | * In this case, expires is actually the dead value. |
| 885 | */ |
| 886 | dead: |
| 887 | sample_to_timespec(timer->it_clock, timer->it.cpu.expires, |
| 888 | &itp->it_value); |
| 889 | return; |
| 890 | } |
| 891 | |
| 892 | /* |
| 893 | * Sample the clock to take the difference with the expiry time. |
| 894 | */ |
| 895 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
| 896 | cpu_clock_sample(timer->it_clock, p, &now); |
| 897 | clear_dead = p->exit_state; |
| 898 | } else { |
| 899 | read_lock(&tasklist_lock); |
| 900 | if (unlikely(p->signal == NULL)) { |
| 901 | /* |
| 902 | * The process has been reaped. |
| 903 | * We can't even collect a sample any more. |
| 904 | * Call the timer disarmed, nothing else to do. |
| 905 | */ |
| 906 | put_task_struct(p); |
| 907 | timer->it.cpu.task = NULL; |
| 908 | timer->it.cpu.expires.sched = 0; |
| 909 | read_unlock(&tasklist_lock); |
| 910 | goto dead; |
| 911 | } else { |
Peter Zijlstra | 3997ad3 | 2009-02-12 15:00:52 +0100 | [diff] [blame] | 912 | cpu_timer_sample_group(timer->it_clock, p, &now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 913 | clear_dead = (unlikely(p->exit_state) && |
| 914 | thread_group_empty(p)); |
| 915 | } |
| 916 | read_unlock(&tasklist_lock); |
| 917 | } |
| 918 | |
| 919 | if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { |
| 920 | if (timer->it.cpu.incr.sched == 0 && |
| 921 | cpu_time_before(timer->it_clock, |
| 922 | timer->it.cpu.expires, now)) { |
| 923 | /* |
| 924 | * Do-nothing timer expired and has no reload, |
| 925 | * so it's as if it was never set. |
| 926 | */ |
| 927 | timer->it.cpu.expires.sched = 0; |
| 928 | itp->it_value.tv_sec = itp->it_value.tv_nsec = 0; |
| 929 | return; |
| 930 | } |
| 931 | /* |
| 932 | * Account for any expirations and reloads that should |
| 933 | * have happened. |
| 934 | */ |
| 935 | bump_cpu_timer(timer, now); |
| 936 | } |
| 937 | |
| 938 | if (unlikely(clear_dead)) { |
| 939 | /* |
| 940 | * We've noticed that the thread is dead, but |
| 941 | * not yet reaped. Take this opportunity to |
| 942 | * drop our task ref. |
| 943 | */ |
| 944 | clear_dead_task(timer, now); |
| 945 | goto dead; |
| 946 | } |
| 947 | |
| 948 | if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) { |
| 949 | sample_to_timespec(timer->it_clock, |
| 950 | cpu_time_sub(timer->it_clock, |
| 951 | timer->it.cpu.expires, now), |
| 952 | &itp->it_value); |
| 953 | } else { |
| 954 | /* |
| 955 | * The timer should have expired already, but the firing |
| 956 | * hasn't taken place yet. Say it's just about to expire. |
| 957 | */ |
| 958 | itp->it_value.tv_nsec = 1; |
| 959 | itp->it_value.tv_sec = 0; |
| 960 | } |
| 961 | } |
| 962 | |
| 963 | /* |
| 964 | * Check for any per-thread CPU timers that have fired and move them off |
| 965 | * the tsk->cpu_timers[N] list onto the firing list. Here we update the |
| 966 | * tsk->it_*_expires values to reflect the remaining thread CPU timers. |
| 967 | */ |
| 968 | static void check_thread_timers(struct task_struct *tsk, |
| 969 | struct list_head *firing) |
| 970 | { |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 971 | int maxfire; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 972 | struct list_head *timers = tsk->cpu_timers; |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 973 | struct signal_struct *const sig = tsk->signal; |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 974 | unsigned long soft; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 975 | |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 976 | maxfire = 20; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 977 | tsk->cputime_expires.prof_exp = cputime_zero; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | while (!list_empty(timers)) { |
Pavel Emelianov | b5e6181 | 2007-05-08 00:30:19 -0700 | [diff] [blame] | 979 | struct cpu_timer_list *t = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 980 | struct cpu_timer_list, |
| 981 | entry); |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 982 | if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) { |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 983 | tsk->cputime_expires.prof_exp = t->expires.cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | break; |
| 985 | } |
| 986 | t->firing = 1; |
| 987 | list_move_tail(&t->entry, firing); |
| 988 | } |
| 989 | |
| 990 | ++timers; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 991 | maxfire = 20; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 992 | tsk->cputime_expires.virt_exp = cputime_zero; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 993 | while (!list_empty(timers)) { |
Pavel Emelianov | b5e6181 | 2007-05-08 00:30:19 -0700 | [diff] [blame] | 994 | struct cpu_timer_list *t = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 995 | struct cpu_timer_list, |
| 996 | entry); |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 997 | if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) { |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 998 | tsk->cputime_expires.virt_exp = t->expires.cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 999 | break; |
| 1000 | } |
| 1001 | t->firing = 1; |
| 1002 | list_move_tail(&t->entry, firing); |
| 1003 | } |
| 1004 | |
| 1005 | ++timers; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1006 | maxfire = 20; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1007 | tsk->cputime_expires.sched_exp = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | while (!list_empty(timers)) { |
Pavel Emelianov | b5e6181 | 2007-05-08 00:30:19 -0700 | [diff] [blame] | 1009 | struct cpu_timer_list *t = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | struct cpu_timer_list, |
| 1011 | entry); |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1012 | if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) { |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1013 | tsk->cputime_expires.sched_exp = t->expires.sched; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | break; |
| 1015 | } |
| 1016 | t->firing = 1; |
| 1017 | list_move_tail(&t->entry, firing); |
| 1018 | } |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1019 | |
| 1020 | /* |
| 1021 | * Check for the special case thread timers. |
| 1022 | */ |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 1023 | soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur); |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1024 | if (soft != RLIM_INFINITY) { |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 1025 | unsigned long hard = |
| 1026 | ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max); |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1027 | |
Peter Zijlstra | 5a52dd5 | 2008-01-25 21:08:32 +0100 | [diff] [blame] | 1028 | if (hard != RLIM_INFINITY && |
| 1029 | tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) { |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1030 | /* |
| 1031 | * At the hard limit, we just die. |
| 1032 | * No need to calculate anything else now. |
| 1033 | */ |
| 1034 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); |
| 1035 | return; |
| 1036 | } |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1037 | if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) { |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1038 | /* |
| 1039 | * At the soft limit, send a SIGXCPU every second. |
| 1040 | */ |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1041 | if (soft < hard) { |
| 1042 | soft += USEC_PER_SEC; |
| 1043 | sig->rlim[RLIMIT_RTTIME].rlim_cur = soft; |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1044 | } |
Hiroshi Shimamoto | 81d50bb | 2008-05-15 19:42:49 -0700 | [diff] [blame] | 1045 | printk(KERN_INFO |
| 1046 | "RT Watchdog Timeout: %s[%d]\n", |
| 1047 | tsk->comm, task_pid_nr(tsk)); |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1048 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); |
| 1049 | } |
| 1050 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1051 | } |
| 1052 | |
Peter Zijlstra | 3fccfd6 | 2009-02-10 16:37:31 +0100 | [diff] [blame] | 1053 | static void stop_process_timers(struct task_struct *tsk) |
| 1054 | { |
| 1055 | struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; |
| 1056 | unsigned long flags; |
| 1057 | |
| 1058 | if (!cputimer->running) |
| 1059 | return; |
| 1060 | |
| 1061 | spin_lock_irqsave(&cputimer->lock, flags); |
| 1062 | cputimer->running = 0; |
| 1063 | spin_unlock_irqrestore(&cputimer->lock, flags); |
| 1064 | } |
| 1065 | |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1066 | static u32 onecputick; |
| 1067 | |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1068 | static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, |
| 1069 | cputime_t *expires, cputime_t cur_time, int signo) |
| 1070 | { |
| 1071 | if (cputime_eq(it->expires, cputime_zero)) |
| 1072 | return; |
| 1073 | |
| 1074 | if (cputime_ge(cur_time, it->expires)) { |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1075 | if (!cputime_eq(it->incr, cputime_zero)) { |
| 1076 | it->expires = cputime_add(it->expires, it->incr); |
| 1077 | it->error += it->incr_error; |
| 1078 | if (it->error >= onecputick) { |
| 1079 | it->expires = cputime_sub(it->expires, |
Stanislaw Gruszka | a42548a | 2009-07-29 12:15:29 +0200 | [diff] [blame] | 1080 | cputime_one_jiffy); |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1081 | it->error -= onecputick; |
| 1082 | } |
Xiao Guangrong | 3f0a525 | 2009-08-10 10:52:30 +0800 | [diff] [blame] | 1083 | } else { |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1084 | it->expires = cputime_zero; |
Xiao Guangrong | 3f0a525 | 2009-08-10 10:52:30 +0800 | [diff] [blame] | 1085 | } |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1086 | |
Xiao Guangrong | 3f0a525 | 2009-08-10 10:52:30 +0800 | [diff] [blame] | 1087 | trace_itimer_expire(signo == SIGPROF ? |
| 1088 | ITIMER_PROF : ITIMER_VIRTUAL, |
| 1089 | tsk->signal->leader_pid, cur_time); |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1090 | __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); |
| 1091 | } |
| 1092 | |
| 1093 | if (!cputime_eq(it->expires, cputime_zero) && |
| 1094 | (cputime_eq(*expires, cputime_zero) || |
| 1095 | cputime_lt(it->expires, *expires))) { |
| 1096 | *expires = it->expires; |
| 1097 | } |
| 1098 | } |
| 1099 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | /* |
| 1101 | * Check for any per-thread CPU timers that have fired and move them |
| 1102 | * off the tsk->*_timers list onto the firing list. Per-thread timers |
| 1103 | * have already been taken off. |
| 1104 | */ |
| 1105 | static void check_process_timers(struct task_struct *tsk, |
| 1106 | struct list_head *firing) |
| 1107 | { |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1108 | int maxfire; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1109 | struct signal_struct *const sig = tsk->signal; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1110 | cputime_t utime, ptime, virt_expires, prof_expires; |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1111 | unsigned long long sum_sched_runtime, sched_expires; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1112 | struct list_head *timers = sig->cpu_timers; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1113 | struct task_cputime cputime; |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1114 | unsigned long soft; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1115 | |
| 1116 | /* |
| 1117 | * Don't sample the current process CPU clocks if there are no timers. |
| 1118 | */ |
| 1119 | if (list_empty(&timers[CPUCLOCK_PROF]) && |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1120 | cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1121 | sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY && |
| 1122 | list_empty(&timers[CPUCLOCK_VIRT]) && |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1123 | cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) && |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 1124 | list_empty(&timers[CPUCLOCK_SCHED])) { |
| 1125 | stop_process_timers(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | return; |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 1127 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1128 | |
| 1129 | /* |
| 1130 | * Collect the current process totals. |
| 1131 | */ |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 1132 | thread_group_cputimer(tsk, &cputime); |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1133 | utime = cputime.utime; |
| 1134 | ptime = cputime_add(utime, cputime.stime); |
| 1135 | sum_sched_runtime = cputime.sum_exec_runtime; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1136 | maxfire = 20; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | prof_expires = cputime_zero; |
| 1138 | while (!list_empty(timers)) { |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1139 | struct cpu_timer_list *tl = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | struct cpu_timer_list, |
| 1141 | entry); |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1142 | if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) { |
| 1143 | prof_expires = tl->expires.cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | break; |
| 1145 | } |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1146 | tl->firing = 1; |
| 1147 | list_move_tail(&tl->entry, firing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1148 | } |
| 1149 | |
| 1150 | ++timers; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1151 | maxfire = 20; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1152 | virt_expires = cputime_zero; |
| 1153 | while (!list_empty(timers)) { |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1154 | struct cpu_timer_list *tl = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1155 | struct cpu_timer_list, |
| 1156 | entry); |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1157 | if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) { |
| 1158 | virt_expires = tl->expires.cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1159 | break; |
| 1160 | } |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1161 | tl->firing = 1; |
| 1162 | list_move_tail(&tl->entry, firing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1163 | } |
| 1164 | |
| 1165 | ++timers; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1166 | maxfire = 20; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | sched_expires = 0; |
| 1168 | while (!list_empty(timers)) { |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1169 | struct cpu_timer_list *tl = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | struct cpu_timer_list, |
| 1171 | entry); |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1172 | if (!--maxfire || sum_sched_runtime < tl->expires.sched) { |
| 1173 | sched_expires = tl->expires.sched; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1174 | break; |
| 1175 | } |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1176 | tl->firing = 1; |
| 1177 | list_move_tail(&tl->entry, firing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1178 | } |
| 1179 | |
| 1180 | /* |
| 1181 | * Check for the special case process timers. |
| 1182 | */ |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1183 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime, |
| 1184 | SIGPROF); |
| 1185 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime, |
| 1186 | SIGVTALRM); |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 1187 | soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur); |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1188 | if (soft != RLIM_INFINITY) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | unsigned long psecs = cputime_to_secs(ptime); |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 1190 | unsigned long hard = |
| 1191 | ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1192 | cputime_t x; |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1193 | if (psecs >= hard) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1194 | /* |
| 1195 | * At the hard limit, we just die. |
| 1196 | * No need to calculate anything else now. |
| 1197 | */ |
| 1198 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); |
| 1199 | return; |
| 1200 | } |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1201 | if (psecs >= soft) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1202 | /* |
| 1203 | * At the soft limit, send a SIGXCPU every second. |
| 1204 | */ |
| 1205 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1206 | if (soft < hard) { |
| 1207 | soft++; |
| 1208 | sig->rlim[RLIMIT_CPU].rlim_cur = soft; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1209 | } |
| 1210 | } |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1211 | x = secs_to_cputime(soft); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | if (cputime_eq(prof_expires, cputime_zero) || |
| 1213 | cputime_lt(x, prof_expires)) { |
| 1214 | prof_expires = x; |
| 1215 | } |
| 1216 | } |
| 1217 | |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1218 | if (!cputime_eq(prof_expires, cputime_zero) && |
| 1219 | (cputime_eq(sig->cputime_expires.prof_exp, cputime_zero) || |
| 1220 | cputime_gt(sig->cputime_expires.prof_exp, prof_expires))) |
| 1221 | sig->cputime_expires.prof_exp = prof_expires; |
| 1222 | if (!cputime_eq(virt_expires, cputime_zero) && |
| 1223 | (cputime_eq(sig->cputime_expires.virt_exp, cputime_zero) || |
| 1224 | cputime_gt(sig->cputime_expires.virt_exp, virt_expires))) |
| 1225 | sig->cputime_expires.virt_exp = virt_expires; |
| 1226 | if (sched_expires != 0 && |
| 1227 | (sig->cputime_expires.sched_exp == 0 || |
| 1228 | sig->cputime_expires.sched_exp > sched_expires)) |
| 1229 | sig->cputime_expires.sched_exp = sched_expires; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1230 | } |
| 1231 | |
| 1232 | /* |
| 1233 | * This is called from the signal code (via do_schedule_next_timer) |
| 1234 | * when the last timer signal was delivered and we have to reload the timer. |
| 1235 | */ |
| 1236 | void posix_cpu_timer_schedule(struct k_itimer *timer) |
| 1237 | { |
| 1238 | struct task_struct *p = timer->it.cpu.task; |
| 1239 | union cpu_time_count now; |
| 1240 | |
| 1241 | if (unlikely(p == NULL)) |
| 1242 | /* |
| 1243 | * The task was cleaned up already, no future firings. |
| 1244 | */ |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1245 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1246 | |
| 1247 | /* |
| 1248 | * Fetch the current sample and update the timer's expiry time. |
| 1249 | */ |
| 1250 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
| 1251 | cpu_clock_sample(timer->it_clock, p, &now); |
| 1252 | bump_cpu_timer(timer, now); |
| 1253 | if (unlikely(p->exit_state)) { |
| 1254 | clear_dead_task(timer, now); |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1255 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1256 | } |
| 1257 | read_lock(&tasklist_lock); /* arm_timer needs it. */ |
| 1258 | } else { |
| 1259 | read_lock(&tasklist_lock); |
| 1260 | if (unlikely(p->signal == NULL)) { |
| 1261 | /* |
| 1262 | * The process has been reaped. |
| 1263 | * We can't even collect a sample any more. |
| 1264 | */ |
| 1265 | put_task_struct(p); |
| 1266 | timer->it.cpu.task = p = NULL; |
| 1267 | timer->it.cpu.expires.sched = 0; |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1268 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | } else if (unlikely(p->exit_state) && thread_group_empty(p)) { |
| 1270 | /* |
| 1271 | * We've noticed that the thread is dead, but |
| 1272 | * not yet reaped. Take this opportunity to |
| 1273 | * drop our task ref. |
| 1274 | */ |
| 1275 | clear_dead_task(timer, now); |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1276 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1277 | } |
Peter Zijlstra | 3997ad3 | 2009-02-12 15:00:52 +0100 | [diff] [blame] | 1278 | cpu_timer_sample_group(timer->it_clock, p, &now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1279 | bump_cpu_timer(timer, now); |
| 1280 | /* Leave the tasklist_lock locked for the call below. */ |
| 1281 | } |
| 1282 | |
| 1283 | /* |
| 1284 | * Now re-arm for the new expiry time. |
| 1285 | */ |
| 1286 | arm_timer(timer, now); |
| 1287 | |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1288 | out_unlock: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1289 | read_unlock(&tasklist_lock); |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1290 | |
| 1291 | out: |
| 1292 | timer->it_overrun_last = timer->it_overrun; |
| 1293 | timer->it_overrun = -1; |
| 1294 | ++timer->it_requeue_pending; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | } |
| 1296 | |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1297 | /** |
| 1298 | * task_cputime_zero - Check a task_cputime struct for all zero fields. |
| 1299 | * |
| 1300 | * @cputime: The struct to compare. |
| 1301 | * |
| 1302 | * Checks @cputime to see if all fields are zero. Returns true if all fields |
| 1303 | * are zero, false if any field is nonzero. |
| 1304 | */ |
| 1305 | static inline int task_cputime_zero(const struct task_cputime *cputime) |
| 1306 | { |
| 1307 | if (cputime_eq(cputime->utime, cputime_zero) && |
| 1308 | cputime_eq(cputime->stime, cputime_zero) && |
| 1309 | cputime->sum_exec_runtime == 0) |
| 1310 | return 1; |
| 1311 | return 0; |
| 1312 | } |
| 1313 | |
| 1314 | /** |
| 1315 | * task_cputime_expired - Compare two task_cputime entities. |
| 1316 | * |
| 1317 | * @sample: The task_cputime structure to be checked for expiration. |
| 1318 | * @expires: Expiration times, against which @sample will be checked. |
| 1319 | * |
| 1320 | * Checks @sample against @expires to see if any field of @sample has expired. |
| 1321 | * Returns true if any field of the former is greater than the corresponding |
| 1322 | * field of the latter if the latter field is set. Otherwise returns false. |
| 1323 | */ |
| 1324 | static inline int task_cputime_expired(const struct task_cputime *sample, |
| 1325 | const struct task_cputime *expires) |
| 1326 | { |
| 1327 | if (!cputime_eq(expires->utime, cputime_zero) && |
| 1328 | cputime_ge(sample->utime, expires->utime)) |
| 1329 | return 1; |
| 1330 | if (!cputime_eq(expires->stime, cputime_zero) && |
| 1331 | cputime_ge(cputime_add(sample->utime, sample->stime), |
| 1332 | expires->stime)) |
| 1333 | return 1; |
| 1334 | if (expires->sum_exec_runtime != 0 && |
| 1335 | sample->sum_exec_runtime >= expires->sum_exec_runtime) |
| 1336 | return 1; |
| 1337 | return 0; |
| 1338 | } |
| 1339 | |
| 1340 | /** |
| 1341 | * fastpath_timer_check - POSIX CPU timers fast path. |
| 1342 | * |
| 1343 | * @tsk: The task (thread) being checked. |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1344 | * |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1345 | * Check the task and thread group timers. If both are zero (there are no |
| 1346 | * timers set) return false. Otherwise snapshot the task and thread group |
| 1347 | * timers and compare them with the corresponding expiration times. Return |
| 1348 | * true if a timer has expired, else return false. |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1349 | */ |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1350 | static inline int fastpath_timer_check(struct task_struct *tsk) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1351 | { |
Oleg Nesterov | ad133ba | 2008-11-17 15:39:47 +0100 | [diff] [blame] | 1352 | struct signal_struct *sig; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1353 | |
Oleg Nesterov | ad133ba | 2008-11-17 15:39:47 +0100 | [diff] [blame] | 1354 | /* tsk == current, ensure it is safe to use ->signal/sighand */ |
| 1355 | if (unlikely(tsk->exit_state)) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1356 | return 0; |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1357 | |
| 1358 | if (!task_cputime_zero(&tsk->cputime_expires)) { |
| 1359 | struct task_cputime task_sample = { |
| 1360 | .utime = tsk->utime, |
| 1361 | .stime = tsk->stime, |
| 1362 | .sum_exec_runtime = tsk->se.sum_exec_runtime |
| 1363 | }; |
| 1364 | |
| 1365 | if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) |
| 1366 | return 1; |
| 1367 | } |
Oleg Nesterov | ad133ba | 2008-11-17 15:39:47 +0100 | [diff] [blame] | 1368 | |
| 1369 | sig = tsk->signal; |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1370 | if (!task_cputime_zero(&sig->cputime_expires)) { |
| 1371 | struct task_cputime group_sample; |
| 1372 | |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 1373 | thread_group_cputimer(tsk, &group_sample); |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1374 | if (task_cputime_expired(&group_sample, &sig->cputime_expires)) |
| 1375 | return 1; |
| 1376 | } |
Oleg Nesterov | 37bebc7 | 2009-03-23 20:34:11 +0100 | [diff] [blame] | 1377 | |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 1378 | return 0; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1379 | } |
| 1380 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | /* |
| 1382 | * This is called from the timer interrupt handler. The irq handler has |
| 1383 | * already updated our counts. We need to check if any timers fire now. |
| 1384 | * Interrupts are disabled. |
| 1385 | */ |
| 1386 | void run_posix_cpu_timers(struct task_struct *tsk) |
| 1387 | { |
| 1388 | LIST_HEAD(firing); |
| 1389 | struct k_itimer *timer, *next; |
| 1390 | |
| 1391 | BUG_ON(!irqs_disabled()); |
| 1392 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1393 | /* |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1394 | * The fast path checks that there are no expired thread or thread |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1395 | * group timers. If that's so, just return. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | */ |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1397 | if (!fastpath_timer_check(tsk)) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1398 | return; |
Ingo Molnar | 5ce73a4 | 2008-09-14 17:11:46 +0200 | [diff] [blame] | 1399 | |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1400 | spin_lock(&tsk->sighand->siglock); |
| 1401 | /* |
| 1402 | * Here we take off tsk->signal->cpu_timers[N] and |
| 1403 | * tsk->cpu_timers[N] all the timers that are firing, and |
| 1404 | * put them on the firing list. |
| 1405 | */ |
| 1406 | check_thread_timers(tsk, &firing); |
| 1407 | check_process_timers(tsk, &firing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1408 | |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1409 | /* |
| 1410 | * We must release these locks before taking any timer's lock. |
| 1411 | * There is a potential race with timer deletion here, as the |
| 1412 | * siglock now protects our private firing list. We have set |
| 1413 | * the firing flag in each timer, so that a deletion attempt |
| 1414 | * that gets the timer lock before we do will give it up and |
| 1415 | * spin until we've taken care of that timer below. |
| 1416 | */ |
| 1417 | spin_unlock(&tsk->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1418 | |
| 1419 | /* |
| 1420 | * Now that all the timers on our list have the firing flag, |
| 1421 | * noone will touch their list entries but us. We'll take |
| 1422 | * each timer's lock before clearing its firing flag, so no |
| 1423 | * timer call will interfere. |
| 1424 | */ |
| 1425 | list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) { |
H Hartley Sweeten | 6e85c5b | 2009-04-29 19:14:32 -0400 | [diff] [blame] | 1426 | int cpu_firing; |
| 1427 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | spin_lock(&timer->it_lock); |
| 1429 | list_del_init(&timer->it.cpu.entry); |
H Hartley Sweeten | 6e85c5b | 2009-04-29 19:14:32 -0400 | [diff] [blame] | 1430 | cpu_firing = timer->it.cpu.firing; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1431 | timer->it.cpu.firing = 0; |
| 1432 | /* |
| 1433 | * The firing flag is -1 if we collided with a reset |
| 1434 | * of the timer, which already reported this |
| 1435 | * almost-firing as an overrun. So don't generate an event. |
| 1436 | */ |
H Hartley Sweeten | 6e85c5b | 2009-04-29 19:14:32 -0400 | [diff] [blame] | 1437 | if (likely(cpu_firing >= 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | cpu_timer_fire(timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1439 | spin_unlock(&timer->it_lock); |
| 1440 | } |
| 1441 | } |
| 1442 | |
| 1443 | /* |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 1444 | * Set one of the process-wide special case CPU timers or RLIMIT_CPU. |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1445 | * The tsk->sighand->siglock must be held by the caller. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | */ |
| 1447 | void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, |
| 1448 | cputime_t *newval, cputime_t *oldval) |
| 1449 | { |
| 1450 | union cpu_time_count now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1451 | |
| 1452 | BUG_ON(clock_idx == CPUCLOCK_SCHED); |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 1453 | cpu_timer_sample_group(clock_idx, tsk, &now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1454 | |
| 1455 | if (oldval) { |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 1456 | /* |
| 1457 | * We are setting itimer. The *oldval is absolute and we update |
| 1458 | * it to be relative, *newval argument is relative and we update |
| 1459 | * it to be absolute. |
| 1460 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | if (!cputime_eq(*oldval, cputime_zero)) { |
| 1462 | if (cputime_le(*oldval, now.cpu)) { |
| 1463 | /* Just about to fire. */ |
Stanislaw Gruszka | a42548a | 2009-07-29 12:15:29 +0200 | [diff] [blame] | 1464 | *oldval = cputime_one_jiffy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | } else { |
| 1466 | *oldval = cputime_sub(*oldval, now.cpu); |
| 1467 | } |
| 1468 | } |
| 1469 | |
| 1470 | if (cputime_eq(*newval, cputime_zero)) |
| 1471 | return; |
| 1472 | *newval = cputime_add(*newval, now.cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1473 | } |
| 1474 | |
| 1475 | /* |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 1476 | * Update expiration cache if we are the earliest timer, or eventually |
| 1477 | * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1478 | */ |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 1479 | switch (clock_idx) { |
| 1480 | case CPUCLOCK_PROF: |
| 1481 | if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval)) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1482 | tsk->signal->cputime_expires.prof_exp = *newval; |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 1483 | break; |
| 1484 | case CPUCLOCK_VIRT: |
| 1485 | if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval)) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1486 | tsk->signal->cputime_expires.virt_exp = *newval; |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame^] | 1487 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | } |
| 1489 | } |
| 1490 | |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1491 | static int do_cpu_nanosleep(const clockid_t which_clock, int flags, |
| 1492 | struct timespec *rqtp, struct itimerspec *it) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1493 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | struct k_itimer timer; |
| 1495 | int error; |
| 1496 | |
| 1497 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1498 | * Set up a temporary timer and then wait for it to go off. |
| 1499 | */ |
| 1500 | memset(&timer, 0, sizeof timer); |
| 1501 | spin_lock_init(&timer.it_lock); |
| 1502 | timer.it_clock = which_clock; |
| 1503 | timer.it_overrun = -1; |
| 1504 | error = posix_cpu_timer_create(&timer); |
| 1505 | timer.it_process = current; |
| 1506 | if (!error) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1507 | static struct itimerspec zero_it; |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1508 | |
| 1509 | memset(it, 0, sizeof *it); |
| 1510 | it->it_value = *rqtp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1511 | |
| 1512 | spin_lock_irq(&timer.it_lock); |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1513 | error = posix_cpu_timer_set(&timer, flags, it, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1514 | if (error) { |
| 1515 | spin_unlock_irq(&timer.it_lock); |
| 1516 | return error; |
| 1517 | } |
| 1518 | |
| 1519 | while (!signal_pending(current)) { |
| 1520 | if (timer.it.cpu.expires.sched == 0) { |
| 1521 | /* |
| 1522 | * Our timer fired and was reset. |
| 1523 | */ |
| 1524 | spin_unlock_irq(&timer.it_lock); |
| 1525 | return 0; |
| 1526 | } |
| 1527 | |
| 1528 | /* |
| 1529 | * Block until cpu_timer_fire (or a signal) wakes us. |
| 1530 | */ |
| 1531 | __set_current_state(TASK_INTERRUPTIBLE); |
| 1532 | spin_unlock_irq(&timer.it_lock); |
| 1533 | schedule(); |
| 1534 | spin_lock_irq(&timer.it_lock); |
| 1535 | } |
| 1536 | |
| 1537 | /* |
| 1538 | * We were interrupted by a signal. |
| 1539 | */ |
| 1540 | sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp); |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1541 | posix_cpu_timer_set(&timer, 0, &zero_it, it); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1542 | spin_unlock_irq(&timer.it_lock); |
| 1543 | |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1544 | if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1545 | /* |
| 1546 | * It actually did fire already. |
| 1547 | */ |
| 1548 | return 0; |
| 1549 | } |
| 1550 | |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1551 | error = -ERESTART_RESTARTBLOCK; |
| 1552 | } |
| 1553 | |
| 1554 | return error; |
| 1555 | } |
| 1556 | |
| 1557 | int posix_cpu_nsleep(const clockid_t which_clock, int flags, |
| 1558 | struct timespec *rqtp, struct timespec __user *rmtp) |
| 1559 | { |
| 1560 | struct restart_block *restart_block = |
| 1561 | ¤t_thread_info()->restart_block; |
| 1562 | struct itimerspec it; |
| 1563 | int error; |
| 1564 | |
| 1565 | /* |
| 1566 | * Diagnose required errors first. |
| 1567 | */ |
| 1568 | if (CPUCLOCK_PERTHREAD(which_clock) && |
| 1569 | (CPUCLOCK_PID(which_clock) == 0 || |
| 1570 | CPUCLOCK_PID(which_clock) == current->pid)) |
| 1571 | return -EINVAL; |
| 1572 | |
| 1573 | error = do_cpu_nanosleep(which_clock, flags, rqtp, &it); |
| 1574 | |
| 1575 | if (error == -ERESTART_RESTARTBLOCK) { |
| 1576 | |
| 1577 | if (flags & TIMER_ABSTIME) |
| 1578 | return -ERESTARTNOHAND; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | /* |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1580 | * Report back to the user the time still remaining. |
| 1581 | */ |
| 1582 | if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1583 | return -EFAULT; |
| 1584 | |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1585 | restart_block->fn = posix_cpu_nsleep_restart; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1586 | restart_block->arg0 = which_clock; |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1587 | restart_block->arg1 = (unsigned long) rmtp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1588 | restart_block->arg2 = rqtp->tv_sec; |
| 1589 | restart_block->arg3 = rqtp->tv_nsec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1590 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1591 | return error; |
| 1592 | } |
| 1593 | |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1594 | long posix_cpu_nsleep_restart(struct restart_block *restart_block) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1595 | { |
| 1596 | clockid_t which_clock = restart_block->arg0; |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1597 | struct timespec __user *rmtp; |
| 1598 | struct timespec t; |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1599 | struct itimerspec it; |
| 1600 | int error; |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1601 | |
| 1602 | rmtp = (struct timespec __user *) restart_block->arg1; |
| 1603 | t.tv_sec = restart_block->arg2; |
| 1604 | t.tv_nsec = restart_block->arg3; |
| 1605 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1606 | restart_block->fn = do_no_restart_syscall; |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1607 | error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it); |
| 1608 | |
| 1609 | if (error == -ERESTART_RESTARTBLOCK) { |
| 1610 | /* |
| 1611 | * Report back to the user the time still remaining. |
| 1612 | */ |
| 1613 | if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) |
| 1614 | return -EFAULT; |
| 1615 | |
| 1616 | restart_block->fn = posix_cpu_nsleep_restart; |
| 1617 | restart_block->arg0 = which_clock; |
| 1618 | restart_block->arg1 = (unsigned long) rmtp; |
| 1619 | restart_block->arg2 = t.tv_sec; |
| 1620 | restart_block->arg3 = t.tv_nsec; |
| 1621 | } |
| 1622 | return error; |
| 1623 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | } |
| 1625 | |
| 1626 | |
| 1627 | #define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED) |
| 1628 | #define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED) |
| 1629 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1630 | static int process_cpu_clock_getres(const clockid_t which_clock, |
| 1631 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1632 | { |
| 1633 | return posix_cpu_clock_getres(PROCESS_CLOCK, tp); |
| 1634 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1635 | static int process_cpu_clock_get(const clockid_t which_clock, |
| 1636 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1637 | { |
| 1638 | return posix_cpu_clock_get(PROCESS_CLOCK, tp); |
| 1639 | } |
| 1640 | static int process_cpu_timer_create(struct k_itimer *timer) |
| 1641 | { |
| 1642 | timer->it_clock = PROCESS_CLOCK; |
| 1643 | return posix_cpu_timer_create(timer); |
| 1644 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1645 | static int process_cpu_nsleep(const clockid_t which_clock, int flags, |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1646 | struct timespec *rqtp, |
| 1647 | struct timespec __user *rmtp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1648 | { |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1649 | return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1650 | } |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1651 | static long process_cpu_nsleep_restart(struct restart_block *restart_block) |
| 1652 | { |
| 1653 | return -EINVAL; |
| 1654 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1655 | static int thread_cpu_clock_getres(const clockid_t which_clock, |
| 1656 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1657 | { |
| 1658 | return posix_cpu_clock_getres(THREAD_CLOCK, tp); |
| 1659 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1660 | static int thread_cpu_clock_get(const clockid_t which_clock, |
| 1661 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1662 | { |
| 1663 | return posix_cpu_clock_get(THREAD_CLOCK, tp); |
| 1664 | } |
| 1665 | static int thread_cpu_timer_create(struct k_itimer *timer) |
| 1666 | { |
| 1667 | timer->it_clock = THREAD_CLOCK; |
| 1668 | return posix_cpu_timer_create(timer); |
| 1669 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1670 | static int thread_cpu_nsleep(const clockid_t which_clock, int flags, |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1671 | struct timespec *rqtp, struct timespec __user *rmtp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1672 | { |
| 1673 | return -EINVAL; |
| 1674 | } |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1675 | static long thread_cpu_nsleep_restart(struct restart_block *restart_block) |
| 1676 | { |
| 1677 | return -EINVAL; |
| 1678 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1679 | |
| 1680 | static __init int init_posix_cpu_timers(void) |
| 1681 | { |
| 1682 | struct k_clock process = { |
| 1683 | .clock_getres = process_cpu_clock_getres, |
| 1684 | .clock_get = process_cpu_clock_get, |
| 1685 | .clock_set = do_posix_clock_nosettime, |
| 1686 | .timer_create = process_cpu_timer_create, |
| 1687 | .nsleep = process_cpu_nsleep, |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1688 | .nsleep_restart = process_cpu_nsleep_restart, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1689 | }; |
| 1690 | struct k_clock thread = { |
| 1691 | .clock_getres = thread_cpu_clock_getres, |
| 1692 | .clock_get = thread_cpu_clock_get, |
| 1693 | .clock_set = do_posix_clock_nosettime, |
| 1694 | .timer_create = thread_cpu_timer_create, |
| 1695 | .nsleep = thread_cpu_nsleep, |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1696 | .nsleep_restart = thread_cpu_nsleep_restart, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1697 | }; |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1698 | struct timespec ts; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1699 | |
| 1700 | register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process); |
| 1701 | register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread); |
| 1702 | |
Stanislaw Gruszka | a42548a | 2009-07-29 12:15:29 +0200 | [diff] [blame] | 1703 | cputime_to_timespec(cputime_one_jiffy, &ts); |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1704 | onecputick = ts.tv_nsec; |
| 1705 | WARN_ON(ts.tv_sec != 0); |
| 1706 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1707 | return 0; |
| 1708 | } |
| 1709 | __initcall(init_posix_cpu_timers); |