From: Mel Gorman Date: Mon, 24 May 2010 21:32:26 +0000 (-0700) Subject: mm: export fragmentation index via debugfs X-Git-Tag: v2.6.35-rc1~377 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f1a5ab1210579e2d3ac8c0c227645823af5aafb0;p=pandora-kernel.git mm: export fragmentation index via debugfs The fragmentation fragmentation index, is only meaningful if an allocation would fail and indicates what the failure is due to. A value of -1 such as in many of the examples above states that the allocation would succeed. If it would fail, the value is between 0 and 1. A value tending towards 0 implies the allocation failed due to a lack of memory. A value tending towards 1 implies it failed due to external fragmentation. For the most part, the huge page size will be the size of interest but not necessarily so it is exported on a per-order and per-zo basis via /sys/kernel/debug/extfrag/extfrag_index > cat /sys/kernel/debug/extfrag/extfrag_index Node 0, zone DMA -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.00 Node 0, zone Normal -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 0.954 Signed-off-by: Mel Gorman Reviewed-by: Minchan Kim Acked-by: Rik van Riel Reviewed-by: Christoph Lameter Cc: KOSAKI Motohiro Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed