From: David Rientjes Date: Tue, 7 Jul 2009 07:14:14 +0000 (-0700) Subject: slub: add option to disable higher order debugging slabs X-Git-Tag: v2.6.32-rc1~695^2^3~6 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fa5ec8a1f66f3c2a3af723abcf8085509c9ee682;p=pandora-kernel.git slub: add option to disable higher order debugging slabs When debugging is enabled, slub requires that additional metadata be stored in slabs for certain options: SLAB_RED_ZONE, SLAB_POISON, and SLAB_STORE_USER. Consequently, it may require that the minimum possible slab order needed to allocate a single object be greater when using these options. The most notable example is for objects that are PAGE_SIZE bytes in size. Higher minimum slab orders may cause page allocation failures when oom or under heavy fragmentation. This patch adds a new slub_debug option, which disables debugging by default for caches that would have resulted in higher minimum orders: slub_debug=O When this option is used on systems with 4K pages, kmalloc-4096, for example, will not have debugging enabled by default even if CONFIG_SLUB_DEBUG_ON is defined because it would have resulted in a order-1 minimum slab order. Reported-by: Larry Finger Tested-by: Larry Finger Cc: Christoph Lameter Signed-off-by: David Rientjes Signed-off-by: Pekka Enberg --- Reading git-diff-tree failed