From 495ab9c045e1b0e5c82951b762257fe1c9d81564 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 26 Jun 2006 13:59:11 +0200 Subject: [PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status During some profiling I noticed that default_idle causes a lot of memory traffic. I think that is caused by the atomic operations to clear/set the polling flag in thread_info. There is actually no reason to make this atomic - only the idle thread does it to itself, other CPUs only read it. So I moved it into ti->status. Converted i386/x86-64/ia64 for now because that was the easiest way to fix ACPI which also manipulates these flags in its idle function. Cc: Nick Piggin Cc: Tony Luck Cc: Len Brown Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/kernel/apm.c | 6 +++--- arch/i386/kernel/process.c | 6 +++--- arch/ia64/kernel/process.c | 4 ++-- arch/x86_64/kernel/process.c | 7 +++---- 4 files changed, 11 insertions(+), 12 deletions(-) (limited to 'arch') diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c index 9e819eb..7c5729d 100644 --- a/arch/i386/kernel/apm.c +++ b/arch/i386/kernel/apm.c @@ -764,9 +764,9 @@ static int apm_do_idle(void) int idled = 0; int polling; - polling = test_thread_flag(TIF_POLLING_NRFLAG); + polling = !!(current_thread_info()->status & TS_POLLING); if (polling) { - clear_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status &= ~TS_POLLING; smp_mb__after_clear_bit(); } if (!need_resched()) { @@ -774,7 +774,7 @@ static int apm_do_idle(void) ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax); } if (polling) - set_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status |= TS_POLLING; if (!idled) return 0; diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index 525432e..6946b06 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -102,7 +102,7 @@ void default_idle(void) local_irq_enable(); if (!hlt_counter && boot_cpu_data.hlt_works_ok) { - clear_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status &= ~TS_POLLING; smp_mb__after_clear_bit(); while (!need_resched()) { local_irq_disable(); @@ -111,7 +111,7 @@ void default_idle(void) else local_irq_enable(); } - set_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status |= TS_POLLING; } else { while (!need_resched()) cpu_relax(); @@ -174,7 +174,7 @@ void cpu_idle(void) { int cpu = smp_processor_id(); - set_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status |= TS_POLLING; /* endless idle loop with no priority at all */ while (1) { diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 355d579..b045c27 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -272,9 +272,9 @@ cpu_idle (void) /* endless idle loop with no priority at all */ while (1) { if (can_do_pal_halt) - clear_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status &= ~TS_POLLING; else - set_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status |= TS_POLLING; if (!need_resched()) { void (*idle)(void); diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c index d6fa414..b596837 100644 --- a/arch/x86_64/kernel/process.c +++ b/arch/x86_64/kernel/process.c @@ -110,7 +110,7 @@ static void default_idle(void) { local_irq_enable(); - clear_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status &= ~TS_POLLING; smp_mb__after_clear_bit(); while (!need_resched()) { local_irq_disable(); @@ -119,7 +119,7 @@ static void default_idle(void) else local_irq_enable(); } - set_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status |= TS_POLLING; } /* @@ -202,8 +202,7 @@ static inline void play_dead(void) */ void cpu_idle (void) { - set_thread_flag(TIF_POLLING_NRFLAG); - + current_thread_info()->status |= TS_POLLING; /* endless idle loop with no priority at all */ while (1) { while (!need_resched()) { -- cgit v1.1