From: Steven Whitehouse Date: Wed, 17 Jan 2007 15:33:23 +0000 (+0000) Subject: [GFS2] Shrink gfs2_inode memory by half X-Git-Tag: v2.6.21-rc1~92^2~35^2~28 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fee852e374fb367c5436b1226eb93b35f8355ed9;p=pandora-kernel.git [GFS2] Shrink gfs2_inode memory by half Here is something I spotted (while looking for something entirely different) the other day. Rather than using a completion in each and every struct gfs2_holder, this removes it in favour of hashed wait queues, thus saving a considerable amount of memory both on the stack (where a number of gfs2_holder structures are allocated) and in particular in the gfs2_inode which has 8 gfs2_holder structures embedded within it. As a result on x86_64 the gfs2_inode shrinks from 2488 bytes to 1912 bytes, a saving of 576 bytes per inode (no thats not a typo!). In actual practice we get a much better result than that since now that a gfs2_inode is under the 2048 byte barrier, we get two per 4k slab page effectively halving the amount of memory required to store gfs2_inodes. Signed-off-by: Steven Whitehouse --- Reading git-diff-tree failed