From: Waiman Long Date: Tue, 23 Jul 2013 21:38:41 +0000 (-0400) Subject: SELinux: Increase ebitmap_node size for 64-bit configuration X-Git-Tag: v3.13-rc1~18^2~52^2~3^2~16 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a767f680e34bf14a36fefbbb6d85783eef99fd57;p=pandora-kernel.git SELinux: Increase ebitmap_node size for 64-bit configuration Currently, the ebitmap_node structure has a fixed size of 32 bytes. On a 32-bit system, the overhead is 8 bytes, leaving 24 bytes for being used as bitmaps. The overhead ratio is 1/4. On a 64-bit system, the overhead is 16 bytes. Therefore, only 16 bytes are left for bitmap purpose and the overhead ratio is 1/2. With a 3.8.2 kernel, a boot-up operation will cause the ebitmap_get_bit() function to be called about 9 million times. The average number of ebitmap_node traversal is about 3.7. This patch increases the size of the ebitmap_node structure to 64 bytes for 64-bit system to keep the overhead ratio at 1/4. This may also improve performance a little bit by making node to node traversal less frequent (< 2) as more bits are available in each node. Signed-off-by: Waiman Long Acked-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Eric Paris --- Reading git-diff-tree failed