From 9d5efe05eb0c904545a28b19c18b949f23334de0 Mon Sep 17 00:00:00 2001 From: Srivatsa Vaddagiri Date: Tue, 8 Jun 2010 14:57:02 +1000 Subject: sched: Fix capacity calculations for SMT4 Handle cpu capacity being reported as 0 on cores with more number of hardware threads. For example on a Power7 core with 4 hardware threads, core power is 1177 and thus power of each hardware thread is 1177/4 = 294. This low power can lead to capacity for each hardware thread being calculated as 0, which leads to tasks bouncing within the core madly! Fix this by reporting capacity for hardware threads as 1, provided their power is not scaled down significantly because of frequency scaling or real-time tasks usage of cpu. Signed-off-by: Srivatsa Vaddagiri Signed-off-by: Michael Neuling Signed-off-by: Peter Zijlstra Cc: Arjan van de Ven LKML-Reference: <20100608045702.21D03CC895@localhost.localdomain> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index a3e5b1cd0438..c731296e5e93 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -857,7 +857,7 @@ struct sched_group { * CPU power of this group, SCHED_LOAD_SCALE being max power for a * single CPU. */ - unsigned int cpu_power; + unsigned int cpu_power, cpu_power_orig; /* * The CPUs this group covers. -- cgit v1.2.3