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authorShuoX Liu <shuox.liu@intel.com>2012-03-28 15:19:11 -0700
committerLen Brown <len.brown@intel.com>2012-03-30 01:52:58 -0400
commit3a53396b0381ec9d5180fd8fe7a681c8ce95fd9a (patch)
tree60a0770554c64250900ccf827ff868b483ae92fe /drivers/cpuidle/cpuidle.c
parent6a6ea0acc9375571a13aa8c4e105a0807e1c16a4 (diff)
downloadlinux-linaro-stable-3a53396b0381ec9d5180fd8fe7a681c8ce95fd9a.tar.gz
cpuidle: add a sysfs entry to disable specific C state for debug purpose.
Some C states of new CPU might be not good. One reason is BIOS might configure them incorrectly. To help developers root cause it quickly, the patch adds a new sysfs entry, so developers could disable specific C state manually. In addition, C state might have much impact on performance tuning, as it takes much time to enter/exit C states, which might delay interrupt processing. With the new debug option, developers could check if a deep C state could impact performance and how much impact it could cause. Also add this option in Documentation/cpuidle/sysfs.txt. [akpm@linux-foundation.org: check kstrtol return value] Signed-off-by: ShuoX Liu <shuox.liu@intel.com> Reviewed-by: Yanmin Zhang <yanmin_zhang@intel.com> Reviewed-and-Tested-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/cpuidle/cpuidle.c')
-rw-r--r--drivers/cpuidle/cpuidle.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 4869b5500234..77304b6b8aef 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -245,6 +245,7 @@ static void poll_idle_init(struct cpuidle_driver *drv)
state->power_usage = -1;
state->flags = 0;
state->enter = poll_idle;
+ state->disable = 0;
}
#else
static void poll_idle_init(struct cpuidle_driver *drv) {}