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authorAndi Kleen <ak@suse.de>2006-06-26 07:59:11 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 13:48:21 -0400
commit495ab9c045e1b0e5c82951b762257fe1c9d81564 (patch)
treef95c376015d340794f64f36fd52f8fa80a1daab7 /arch/i386/kernel
parentd9005b52de7bc9b20afa93e06d3e15843bafc12f (diff)
[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 <npiggin@novell.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Len Brown <len.brown@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/kernel')
-rw-r--r--arch/i386/kernel/apm.c6
-rw-r--r--arch/i386/kernel/process.c6
2 files changed, 6 insertions, 6 deletions
diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c
index 9e819eb68229..7c5729d1fd06 100644
--- a/arch/i386/kernel/apm.c
+++ b/arch/i386/kernel/apm.c
@@ -764,9 +764,9 @@ static int apm_do_idle(void)
764 int idled = 0; 764 int idled = 0;
765 int polling; 765 int polling;
766 766
767 polling = test_thread_flag(TIF_POLLING_NRFLAG); 767 polling = !!(current_thread_info()->status & TS_POLLING);
768 if (polling) { 768 if (polling) {
769 clear_thread_flag(TIF_POLLING_NRFLAG); 769 current_thread_info()->status &= ~TS_POLLING;
770 smp_mb__after_clear_bit(); 770 smp_mb__after_clear_bit();
771 } 771 }
772 if (!need_resched()) { 772 if (!need_resched()) {
@@ -774,7 +774,7 @@ static int apm_do_idle(void)
774 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax); 774 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
775 } 775 }
776 if (polling) 776 if (polling)
777 set_thread_flag(TIF_POLLING_NRFLAG); 777 current_thread_info()->status |= TS_POLLING;
778 778
779 if (!idled) 779 if (!idled)
780 return 0; 780 return 0;
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 525432e3fef7..6946b06e2784 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -102,7 +102,7 @@ void default_idle(void)
102 local_irq_enable(); 102 local_irq_enable();
103 103
104 if (!hlt_counter && boot_cpu_data.hlt_works_ok) { 104 if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
105 clear_thread_flag(TIF_POLLING_NRFLAG); 105 current_thread_info()->status &= ~TS_POLLING;
106 smp_mb__after_clear_bit(); 106 smp_mb__after_clear_bit();
107 while (!need_resched()) { 107 while (!need_resched()) {
108 local_irq_disable(); 108 local_irq_disable();
@@ -111,7 +111,7 @@ void default_idle(void)
111 else 111 else
112 local_irq_enable(); 112 local_irq_enable();
113 } 113 }
114 set_thread_flag(TIF_POLLING_NRFLAG); 114 current_thread_info()->status |= TS_POLLING;
115 } else { 115 } else {
116 while (!need_resched()) 116 while (!need_resched())
117 cpu_relax(); 117 cpu_relax();
@@ -174,7 +174,7 @@ void cpu_idle(void)
174{ 174{
175 int cpu = smp_processor_id(); 175 int cpu = smp_processor_id();
176 176
177 set_thread_flag(TIF_POLLING_NRFLAG); 177 current_thread_info()->status |= TS_POLLING;
178 178
179 /* endless idle loop with no priority at all */ 179 /* endless idle loop with no priority at all */
180 while (1) { 180 while (1) {