Messages in this thread | | | Date | Tue, 09 Feb 2010 11:48:20 -0500 | From | Rik van Riel <> | Subject | Re: [PATCH] fs: buffer_head, remove kmem_cache constructor to reduce memory usage under slub |
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On 02/09/2010 08:29 AM, Richard Kennedy wrote: > fs: Remove the buffer_head kmem_cache constructor to reduce memory usage > under slub. > > When using slub, having a kmem_cache constructor forces slub to add a > free pointer to the size of the cached object, which can have a > significant impact to the number of small objects that can fit into a > slab. > > As buffer_head is relatively small and we can have large numbers of > them, removing the constructor is a definite win. > > On x86_64 removing the constructor gives me 39 objects/slab, 3 more than > without the patch. And on x86_32 73 objects/slab, which is 9 more. > > As alloc_buffer_head() already initializes each new object there is very > little difference in actual code run. > > Signed-off-by: Richard Kennedy<richard@rsk.demon.co.uk>
Reviewed-by: Rik van Riel <riel@redhat.com>
-- All rights reversed.
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