From: Venkatesh Pallipadi <venki@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>,
Aaron Durbin <adurbin@google.com>, Paul Turner <pjt@google.com>,
Yong Zhang <yong.zhang0@gmail.com>,
Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org,
Venkatesh Pallipadi <venki@google.com>
Subject: [PATCH 3/4] x86: Extend IPIless wake to C1_mwait and poll_idle
Date: Fri, 24 Feb 2012 14:33:19 -0800 [thread overview]
Message-ID: <1330122800-834-4-git-send-email-venki@google.com> (raw)
In-Reply-To: <1330122800-834-1-git-send-email-venki@google.com>
poll_idle(), mwait_idle() [which is used for C1 mwait] and any other
polling based idle loops can also use the IPIless wakeup logic added
with mwait_idle_with_hints() in the earlier patch.
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
---
arch/x86/kernel/process.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 99a8109..43bb0a5 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -22,6 +22,7 @@
#include <asm/uaccess.h>
#include <asm/i387.h>
#include <asm/debugreg.h>
+#include <asm/ipiless_wake.h>
struct kmem_cache *task_xstate_cachep;
EXPORT_SYMBOL_GPL(task_xstate_cachep);
@@ -445,7 +446,8 @@ EXPORT_SYMBOL_GPL(cpu_idle_wait);
/* Default MONITOR/MWAIT with no hints, used for default C1 state */
static void mwait_idle(void)
{
- if (!need_resched()) {
+ enter_ipiless_idle();
+ if (!is_ipiless_wakeup_pending()) {
trace_power_start(POWER_CSTATE, 1, smp_processor_id());
trace_cpu_idle(1, smp_processor_id());
if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR))
@@ -453,7 +455,7 @@ static void mwait_idle(void)
__monitor((void *)¤t_thread_info()->flags, 0, 0);
smp_mb();
- if (!need_resched())
+ if (!is_ipiless_wakeup_pending())
__sti_mwait(0, 0);
else
local_irq_enable();
@@ -461,6 +463,7 @@ static void mwait_idle(void)
trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
} else
local_irq_enable();
+ exit_ipiless_idle();
}
/*
@@ -470,13 +473,15 @@ static void mwait_idle(void)
*/
static void poll_idle(void)
{
+ enter_ipiless_idle();
trace_power_start(POWER_CSTATE, 0, smp_processor_id());
trace_cpu_idle(0, smp_processor_id());
local_irq_enable();
- while (!need_resched())
+ while (!is_ipiless_wakeup_pending())
cpu_relax();
trace_power_end(smp_processor_id());
trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+ exit_ipiless_idle();
}
/*
--
1.7.7.3
next prev parent reply other threads:[~2012-02-24 22:34 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-24 22:33 [PATCH 0/4] Extend mwait idle to optimize away CAL and RES interrupts to an idle CPU -v2 Venkatesh Pallipadi
2012-02-24 22:33 ` [PATCH 1/4] tile, ia64, x86: TS_POLLING cleanup Venkatesh Pallipadi
2012-02-24 22:33 ` [PATCH 2/4] x86: Mwait idle optimization to avoid CAL+RES IPIs -v2 Venkatesh Pallipadi
2012-02-24 22:33 ` Venkatesh Pallipadi [this message]
2012-02-24 22:33 ` [PATCH 4/4] x86: Optimize try_ipiless_wakeup avoid idle task lookup Venkatesh Pallipadi
2012-02-27 7:32 ` [PATCH 0/4] Extend mwait idle to optimize away CAL and RES interrupts to an idle CPU -v2 Ingo Molnar
2012-02-27 18:21 ` Venki Pallipadi
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