From d7a5752c0c19750312efab3a2a80d350e11fa4a2 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Mon, 24 May 2010 14:32:25 -0700 Subject: [PATCH] mm: export unusable free space index via debugfs The unusable free space index measures how much of the available free memory cannot be used to satisfy an allocation of a given size and is a value between 0 and 1. The higher the value, the more of free memory is unusable and by implication, the worse the external fragmentation is. 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-zone basis via /sys/kernel/debug/extfrag/unusable_index. > cat /sys/kernel/debug/extfrag/unusable_index Node 0, zone DMA 0.000 0.000 0.000 0.001 0.005 0.013 0.021 0.037 0.037 0.101 0.230 Node 0, zone Normal 0.000 0.000 0.000 0.001 0.002 0.002 0.005 0.015 0.028 0.028 0.054 [akpm@linux-foundation.org: Fix allnoconfig] Signed-off-by: Mel Gorman Reviewed-by: Minchan Kim Reviewed-by: KOSAKI Motohiro Reviewed-by: Christoph Lameter Cc: Rik van Riel Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed