[PATCH] oom-killer disable for iscsi/lvm2/multipath userland critical sections
Andrea Arcangeli [Sat, 16 Apr 2005 22:24:05 +0000 (15:24 -0700)]
iscsi/lvm2/multipath needs guaranteed protection from the oom-killer, so
make the magical value of -17 in /proc/<pid>/oom_adj defeat the oom-killer
altogether.

(akpm: we still need to document oom_adj and friends in
Documentation/filesystems/proc.txt!)

Signed-off-by: Andrea Arcangeli <andrea@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/proc/base.c
include/linux/mm.h
mm/oom_kill.c

index dad8ea4..39fd336 100644 (file)
@@ -751,7 +751,7 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
        if (copy_from_user(buffer, buf, count))
                return -EFAULT;
        oom_adjust = simple_strtol(buffer, &end, 0);
-       if (oom_adjust < -16 || oom_adjust > 15)
+       if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
                return -EINVAL;
        if (*end == '\n')
                end++;
index 6a93137..85f7d1b 100644 (file)
@@ -857,5 +857,8 @@ int in_gate_area_no_task(unsigned long addr);
 #define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
 #endif /* __HAVE_ARCH_GATE_AREA */
 
+/* /proc/<pid>/oom_adj set to -17 protects from the oom-killer */
+#define OOM_DISABLE -17
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_MM_H */
index 9595a0f..4bbb1cb 100644 (file)
@@ -145,7 +145,7 @@ static struct task_struct * select_bad_process(void)
        do_posix_clock_monotonic_gettime(&uptime);
        do_each_thread(g, p)
                /* skip the init task with pid == 1 */
-               if (p->pid > 1) {
+               if (p->pid > 1 && p->oomkilladj != OOM_DISABLE) {
                        unsigned long points;
 
                        /*