sched: Fix sched_mv_power_savings for !SMT
Vaidyanathan Srinivasan [Mon, 8 Feb 2010 10:05:55 +0000 (15:05 +0530)]
Fix for sched_mc_powersavigs for pre-Nehalem platforms.
Child sched domain should clear SD_PREFER_SIBLING if parent will have
SD_POWERSAVINGS_BALANCE because they are contradicting.

Sets the flags correctly based on sched_mc_power_savings.

Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100208100555.GD2931@dirshya.in.ibm.com>
Cc: stable@kernel.org [2.6.32.x]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/sched.h

index 78efe7c..1f5fa53 100644 (file)
@@ -878,7 +878,10 @@ static inline int sd_balance_for_mc_power(void)
        if (sched_smt_power_savings)
                return SD_POWERSAVINGS_BALANCE;
 
-       return SD_PREFER_SIBLING;
+       if (!sched_mc_power_savings)
+               return SD_PREFER_SIBLING;
+
+       return 0;
 }
 
 static inline int sd_balance_for_package_power(void)