Revision 3a53396b0381ec9d5180fd8fe7a681c8ce95fd9a authored by ShuoX Liu on 28 March 2012, 22:19:11 UTC, committed by Len Brown on 30 March 2012, 05:52:58 UTC
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>
1 parent 6a6ea0a
Raw File
rtmutex.h
/*
 * RT-Mutexes: blocking mutual exclusion locks with PI support
 *
 * started by Ingo Molnar and Thomas Gleixner:
 *
 *  Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
 *
 * This file contains macros used solely by rtmutex.c.
 * Non-debug version.
 */

#define rt_mutex_deadlock_check(l)			(0)
#define rt_mutex_deadlock_account_lock(m, t)		do { } while (0)
#define rt_mutex_deadlock_account_unlock(l)		do { } while (0)
#define debug_rt_mutex_init_waiter(w)			do { } while (0)
#define debug_rt_mutex_free_waiter(w)			do { } while (0)
#define debug_rt_mutex_lock(l)				do { } while (0)
#define debug_rt_mutex_proxy_lock(l,p)			do { } while (0)
#define debug_rt_mutex_proxy_unlock(l)			do { } while (0)
#define debug_rt_mutex_unlock(l)			do { } while (0)
#define debug_rt_mutex_init(m, n)			do { } while (0)
#define debug_rt_mutex_deadlock(d, a ,l)		do { } while (0)
#define debug_rt_mutex_print_deadlock(w)		do { } while (0)
#define debug_rt_mutex_detect_deadlock(w,d)		(d)
#define debug_rt_mutex_reset_waiter(w)			do { } while (0)
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