Srikar Dronamraju 0ad4e3dfe6 sched/numa: Modify migrate_swap() to accept additional parameters
There are checks in migrate_swap_stop() that check if the task/CPU
combination is as per migrate_swap_arg before migrating.

However atleast one of the two tasks to be swapped by migrate_swap() could
have migrated to a completely different CPU before updating the
migrate_swap_arg. The new CPU where the task is currently running could
be a different node too. If the task has migrated, numa balancer might
end up placing a task in a wrong node.  Instead of achieving node
consolidation, it may end up spreading the load across nodes.

To avoid that pass the CPUs as additional parameters.

While here, place migrate_swap under CONFIG_NUMA_BALANCING.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
JVMS  LAST_PATCH  WITH_PATCH  %CHANGE
16    25377.3     25226.6     -0.59
1     72287       73326       1.437

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1529514181-9842-10-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-25 11:41:07 +02:00
..
2018-07-15 23:51:21 +02:00
2018-06-20 11:35:56 +02:00