From: Peter Zijlstra Date: Mon, 7 Oct 2013 10:29:33 +0000 (+0100) Subject: sched/numa: Avoid migrating tasks that are placed on their preferred node X-Git-Tag: omap-for-v3.13/fixes-for-merge-window-take2~40^2~35 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0ec8aa00f2b4dc457836ef4e2662b02483e94fb7;p=pandora-kernel.git sched/numa: Avoid migrating tasks that are placed on their preferred node This patch classifies scheduler domains and runqueues into types depending the number of tasks that are about their NUMA placement and the number that are currently running on their preferred node. The types are regular: There are tasks running that do not care about their NUMA placement. remote: There are tasks running that care about their placement but are currently running on a node remote to their ideal placement all: No distinction To implement this the patch tracks the number of tasks that are optimally NUMA placed (rq->nr_preferred_running) and the number of tasks running that care about their placement (nr_numa_running). The load balancer uses this information to avoid migrating idea placed NUMA tasks as long as better options for load balancing exists. For example, it will not consider balancing between a group whose tasks are all perfectly placed and a group with remote tasks. Signed-off-by: Peter Zijlstra Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Srikar Dronamraju Link: http://lkml.kernel.org/r/1381141781-10992-56-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed