Rik van Riel 9722c2dac7 sched: Calculate effective load even if local weight is 0 ... Thomas Hellstrom bisected a regression where erratic 3D performance is experienced on virtual machines as measured by glxgears. It identified commit 58d081b5 ("sched/numa: Avoid overloading CPUs on a preferred NUMA node") as the problem which had modified the behaviour of effective_load. Effective load calculates the difference to the system-wide load if a scheduling entity was moved to another CPU. The task group is not heavier as a result of the move but overall system load can increase/decrease as a result of the change. Commit 58d081b5 ("sched/numa: Avoid overloading CPUs on a preferred NUMA node") changed effective_load to make it suitable for calculating if a particular NUMA node was compute overloaded. To reduce the cost of the function, it assumed that a current sched entity weight of 0 was uninteresting but that is not the case. wake_affine() uses a weight of 0 for sync wakeups on the grounds that it is assuming the waking task will sleep and not contribute to load in the near future. In this case, we still want to calculate the effective load of the sched entity hierarchy. As effective_load is no longer used by task_numa_compare since commit fb13c7ee (sched/numa: Use a system-wide search to find swap/migration candidates), this patch simply restores the historical behaviour. Reported-and-tested-by: Thomas Hellstrom <thellstrom@vmware.com> Signed-off-by: Rik van Riel <riel@redhat.com> [ Wrote changelog] Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140106113912.GC6178@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>		2014-01-12 09:22:15 +01:00
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auto_group.c
auto_group.h
clock.c
completion.c
core.c	sched: Assign correct scheduling domain to 'sd_llc'	2013-12-17 15:08:43 +01:00
cpuacct.c
cpuacct.h
cpupri.c
cpupri.h
cputime.c
debug.c
fair.c	sched: Calculate effective load even if local weight is 0	2014-01-12 09:22:15 +01:00
features.h
idle_task.c
Makefile
proc.c
rt.c	sched/rt: Fix rq's cpupri leak while enqueue/dequeue child RT entities	2013-12-17 15:08:44 +01:00
sched.h
stats.c
stats.h
stop_task.c
wait.c