linux-kernel - [PATCH 6/8] acpi_pad: uses MONITOR/MWAIT, so it doesn't need to clear TS

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Date:	Wed, 26 May 2010 22:42:29 -0400
From:	Len Brown <lenb@...nel.org>
To:	x86@...nel.org, linux-pm@...ts.linux-foundation.org
Cc:	linux-kernel@...r.kernel.org, Len Brown <len.brown@...el.com>,
	Shaohua Li <shaohua.li@...el.com>
Subject: [PATCH 6/8] acpi_pad: uses MONITOR/MWAIT,
 so it doesn't need to clear TS_POLLING

From: Len Brown <len.brown@...el.com>

api_pad exclusively uses MONITOR/MWAIT to sleep in idle,
so it does not need the wakeup IPI during idle sleep
that is provoked by clearing TS_POLLING.

Signed-off-by: Len Brown <len.brown@...el.com>
Cc: Shaohua Li <shaohua.li@...el.com>
---
 drivers/acpi/acpi_pad.c |    9 ---------
 1 files changed, 0 insertions(+), 9 deletions(-)

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index 6212213..7edf053 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -168,13 +168,6 @@ 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()) {
@@ -200,8 +193,6 @@ 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
-- 
1.6.0.6

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