From a68a0a352a0209467268dfddffe02db08b97ddb4 Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Fri, 19 Oct 2012 08:32:51 -0400 Subject: GFS2: Speed up gfs2_rbm_from_block This patch is a rewrite of function gfs2_rbm_from_block. Rather than looping to find the right bitmap, the code now does a few simple math calculations. I compared the performance of both algorithms side by side and the new algorithm is noticeably faster. Sample instrumentation output from a "fast" machine: 5 million calls: millisec spent: Orig: 166 New: 113 5 million calls: millisec spent: Orig: 189 New: 114 In addition, I ran postmark (on a somewhat slowr CPU) before the after the new algorithm was put in place and postmark showed a decent improvement: Before the new algorithm: ------------------------- Time: 645 seconds total 584 seconds of transactions (171 per second) Files: 150087 created (232 per second) Creation alone: 100000 files (2083 per second) Mixed with transactions: 50087 files (85 per second) 49995 read (85 per second) 49991 appended (85 per second) 150087 deleted (232 per second) Deletion alone: 100174 files (7705 per second) Mixed with transactions: 49913 files (85 per second) Data: 273.42 megabytes read (434.08 kilobytes per second) 852.13 megabytes written (1.32 megabytes per second) With the new algorithm: ----------------------- Time: 599 seconds total 530 seconds of transactions (188 per second) Files: 150087 created (250 per second) Creation alone: 100000 files (1886 per second) Mixed with transactions: 50087 files (94 per second) 49995 read (94 per second) 49991 appended (94 per second) 150087 deleted (250 per second) Deletion alone: 100174 files (6260 per second) Mixed with transactions: 49913 files (94 per second) Data: 273.42 megabytes read (467.42 kilobytes per second) 852.13 megabytes written (1.42 megabytes per second) Signed-off-by: Bob Peterson Signed-off-by: Steven Whitehouse --- fs/gfs2/ops_fstype.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/gfs2/ops_fstype.c') diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index e443966c8106..0e3554edb8f2 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -278,6 +278,9 @@ static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent) sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(struct gfs2_quota_change); + sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize - + sizeof(struct gfs2_meta_header)) + * GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */ /* Compute maximum reservation required to add a entry to a directory */ -- cgit v1.2.3