From e42c8ff2999de1239a57d434bfbd8e9f2a56e814 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Mon, 12 Nov 2012 09:17:07 +0000 Subject: [PATCH] mm: numa: Use a two-stage filter to restrict pages being migrated for unlikely task<->node relationships Note: This two-stage filter was taken directly from the sched/numa patch "sched, numa, mm: Add the scanning page fault machinery" but is only a partial extraction. As the end result is not necessarily recognisable, the signed-offs-by had to be removed. Will be added back if requested. While it is desirable that all threads in a process run on its home node, this is not always possible or necessary. There may be more threads than exist within the node or the node might over-subscribed with unrelated processes. This can cause a situation whereby a page gets migrated off its home node because the threads clearing pte_numa were running off-node. This patch uses page->last_nid to build a two-stage filter before pages get migrated to avoid problems with short or unlikely task<->node relationships. Signed-off-by: Mel Gorman --- Reading git-format-patch failed