From 3a53396b0381ec9d5180fd8fe7a681c8ce95fd9a Mon Sep 17 00:00:00 2001 From: ShuoX Liu Date: Wed, 28 Mar 2012 15:19:11 -0700 Subject: 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 Reviewed-by: Yanmin Zhang Reviewed-and-Tested-by: Deepthi Dharwar Signed-off-by: Andrew Morton Signed-off-by: Len Brown --- include/linux/cpuidle.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 927db28a2a4c..ca4e4983773f 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -46,6 +46,7 @@ struct cpuidle_state { unsigned int exit_latency; /* in US */ unsigned int power_usage; /* in mW */ unsigned int target_residency; /* in US */ + unsigned int disable; int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, -- cgit v1.2.3