From 54335b1fca27b84baa75b1f45985d98262003837 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Thu, 1 Sep 2011 13:31:59 +0100 Subject: GFS2: Cache the most recently used resource group in the inode This means that after the initial allocation for any inode, the last used resource group is cached in the inode for future use. This drastically reduces the number of lookups of resource groups in the common case, and this the contention on that data structure. The allocation algorithm is the same as previously, except that we always check to see if the goal block is within the cached rgrp first before going to the rbtree to look one up. Signed-off-by: Steven Whitehouse --- fs/gfs2/trans.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs/gfs2/trans.h') diff --git a/fs/gfs2/trans.h b/fs/gfs2/trans.h index 980c5c0..f8f101e 100644 --- a/fs/gfs2/trans.h +++ b/fs/gfs2/trans.h @@ -28,10 +28,12 @@ struct gfs2_glock; /* reserve either the number of blocks to be allocated plus the rg header * block, or all of the blocks in the rg, whichever is smaller */ -static inline unsigned int gfs2_rg_blocks(const struct gfs2_alloc *al) +static inline unsigned int gfs2_rg_blocks(const struct gfs2_inode *ip) { - return (al->al_requested < al->al_rgd->rd_length)? - al->al_requested + 1 : al->al_rgd->rd_length; + const struct gfs2_alloc *al = ip->i_alloc; + if (al->al_requested < ip->i_rgd->rd_length) + return al->al_requested + 1; + return ip->i_rgd->rd_length; } extern int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks, -- cgit v1.1