tile: Use generic idle loop
Thomas Gleixner [Thu, 21 Mar 2013 21:50:01 +0000 (22:50 +0100)]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Link: http://lkml.kernel.org/r/20130321215235.348460344@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/tile/Kconfig
arch/tile/kernel/process.c
arch/tile/kernel/smpboot.c

index 25877ae..85b2ede 100644 (file)
@@ -22,6 +22,7 @@ config TILE
        select ARCH_HAVE_NMI_SAFE_CMPXCHG
        select GENERIC_CLOCKEVENTS
        select MODULES_USE_ELF_RELA
+       select GENERIC_IDLE_LOOP
 
 # FIXME: investigate whether we need/want these options.
 #      select HAVE_IOREMAP_PROT
index caf93ae..80b2a18 100644 (file)
 #include <arch/abi.h>
 #include <arch/sim_def.h>
 
-
 /*
  * Use the (x86) "idle=poll" option to prefer low latency when leaving the
  * idle loop over low power while in the idle loop, e.g. if we have
  * one thread per core and we want to get threads out of futex waits fast.
  */
-static int no_idle_nap;
 static int __init idle_setup(char *str)
 {
        if (!str)
@@ -54,64 +52,19 @@ static int __init idle_setup(char *str)
 
        if (!strcmp(str, "poll")) {
                pr_info("using polling idle threads.\n");
-               no_idle_nap = 1;
-       } else if (!strcmp(str, "halt"))
-               no_idle_nap = 0;
-       else
-               return -1;
-
-       return 0;
+               cpu_idle_poll_ctrl(true);
+               return 0;
+       } else if (!strcmp(str, "halt")) {
+               return 0;
+       }
+       return -1;
 }
 early_param("idle", idle_setup);
 
-/*
- * The idle thread. There's no useful work to be
- * done, so just try to conserve power and have a
- * low exit latency (ie sit in a loop waiting for
- * somebody to say that they'd like to reschedule)
- */
-void cpu_idle(void)
+void arch_cpu_idle(void)
 {
-       int cpu = smp_processor_id();
-
-
-       current_thread_info()->status |= TS_POLLING;
-
-       if (no_idle_nap) {
-               while (1) {
-                       while (!need_resched())
-                               cpu_relax();
-                       schedule();
-               }
-       }
-
-       /* endless idle loop with no priority at all */
-       while (1) {
-               tick_nohz_idle_enter();
-               rcu_idle_enter();
-               while (!need_resched()) {
-                       if (cpu_is_offline(cpu))
-                               BUG();  /* no HOTPLUG_CPU */
-
-                       local_irq_disable();
-                       __get_cpu_var(irq_stat).idle_timestamp = jiffies;
-                       current_thread_info()->status &= ~TS_POLLING;
-                       /*
-                        * TS_POLLING-cleared state must be visible before we
-                        * test NEED_RESCHED:
-                        */
-                       smp_mb();
-
-                       if (!need_resched())
-                               _cpu_idle();
-                       else
-                               local_irq_enable();
-                       current_thread_info()->status |= TS_POLLING;
-               }
-               rcu_idle_exit();
-               tick_nohz_idle_exit();
-               schedule_preempt_disabled();
-       }
+       __get_cpu_var(irq_stat).idle_timestamp = jiffies;
+       _cpu_idle();
 }
 
 /*
index 11c0190..44bab29 100644 (file)
@@ -207,7 +207,7 @@ void __cpuinit online_secondary(void)
        /* Set up tile-timer clock-event device on this cpu */
        setup_tile_timer();
 
-       cpu_idle();
+       cpu_startup_entry(CPUHP_ONLINE);
 }
 
 int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)