From 0dc8153cfebac68c9523b8852b14f10b31209f08 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 21 Mar 2013 22:50:01 +0100 Subject: [PATCH] tile: Use generic idle loop Signed-off-by: Thomas Gleixner Cc: Linus Torvalds Cc: Rusty Russell Cc: Paul McKenney Cc: Peter Zijlstra Reviewed-by: Cc: Srivatsa S. Bhat Cc: Magnus Damm Acked-by: Chris Metcalf Link: http://lkml.kernel.org/r/20130321215235.348460344@linutronix.de Signed-off-by: Thomas Gleixner --- arch/tile/Kconfig | 1 + arch/tile/kernel/process.c | 65 ++++++-------------------------------- arch/tile/kernel/smpboot.c | 2 +- 3 files changed, 11 insertions(+), 57 deletions(-) diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig index 25877aebc685..85b2edeade31 100644 --- a/arch/tile/Kconfig +++ b/arch/tile/Kconfig @@ -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 diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c index caf93ae11793..80b2a18deb87 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -40,13 +40,11 @@ #include #include - /* * 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(); } /* diff --git a/arch/tile/kernel/smpboot.c b/arch/tile/kernel/smpboot.c index 11c0190bb096..44bab29bf2f3 100644 --- a/arch/tile/kernel/smpboot.c +++ b/arch/tile/kernel/smpboot.c @@ -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) -- 2.39.5