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authorDavid S. Miller <davem@davemloft.net>2010-06-26 10:27:00 -0700
committerDavid S. Miller <davem@davemloft.net>2010-06-26 10:27:00 -0700
commitc67dda14389205f0a223c5089307495290939b3b (patch)
treefad0bb26b28703d02a22ebdd44d94eabac4a2ade /drivers/acpi/acpi_pad.c
parent43bc2db47292a824152145253b1dd2847e7312a3 (diff)
parent7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff)
downloadlinux-rt-c67dda14389205f0a223c5089307495290939b3b.tar.gz
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Diffstat (limited to 'drivers/acpi/acpi_pad.c')
-rw-r--r--drivers/acpi/acpi_pad.c22
1 files changed, 11 insertions, 11 deletions
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index 62122134693b..d269a8f3329c 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -43,6 +43,10 @@ static DEFINE_MUTEX(isolated_cpus_lock);
#define CPUID5_ECX_EXTENSIONS_SUPPORTED (0x1)
#define CPUID5_ECX_INTERRUPT_BREAK (0x2)
static unsigned long power_saving_mwait_eax;
+
+static unsigned char tsc_detected_unstable;
+static unsigned char tsc_marked_unstable;
+
static void power_saving_mwait_init(void)
{
unsigned int eax, ebx, ecx, edx;
@@ -87,8 +91,8 @@ static void power_saving_mwait_init(void)
/*FALL THROUGH*/
default:
- /* TSC could halt in idle, so notify users */
- mark_tsc_unstable("TSC halts in idle");
+ /* TSC could halt in idle */
+ tsc_detected_unstable = 1;
}
#endif
}
@@ -168,16 +172,14 @@ static int power_saving_thread(void *data)
do_sleep = 0;
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we test
- * NEED_RESCHED:
- */
- smp_mb();
-
expire_time = jiffies + HZ * (100 - idle_pct) / 100;
while (!need_resched()) {
+ if (tsc_detected_unstable && !tsc_marked_unstable) {
+ /* TSC could halt in idle, so notify users */
+ mark_tsc_unstable("TSC halts in idle");
+ tsc_marked_unstable = 1;
+ }
local_irq_disable();
cpu = smp_processor_id();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
@@ -200,8 +202,6 @@ static int power_saving_thread(void *data)
}
}
- current_thread_info()->status |= TS_POLLING;
-
/*
* current sched_rt has threshold for rt task running time.
* When a rt task uses 95% CPU time, the rt thread will be