From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Whitehouse Date: Fri, 19 Oct 2012 14:17:32 +0100 Subject: [Cluster-devel] [GFS2 PATCH][TRY #2] GFS2: Speed up gfs2_rbm_from_block In-Reply-To: <238753109.21353665.1350649971170.JavaMail.root@redhat.com> References: <238753109.21353665.1350649971170.JavaMail.root@redhat.com> Message-ID: <1350652652.2754.20.camel@menhir> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, That looks good, and good to see that it makes a difference to at least one workload, as well as the reduction in time. Now in the -nmw git tree. Thanks, Steve. On Fri, 2012-10-19 at 08:32 -0400, Bob Peterson wrote: > Hi, > > This is my second attempt at this patch, following Steve's suggestions. > > 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) > > Regards, > > Bob Peterson > Red Hat File Systems > > Signed-off-by: Bob Peterson > --- > commit f7abb1edc9e61eb5ff5ae9fa1a3964b10f3aa553 > Author: Bob Peterson > Date: Wed Oct 17 09:59:43 2012 -0500 > > 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. > > diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h > index 3d469d3..24bb0b8 100644 > --- a/fs/gfs2/incore.h > +++ b/fs/gfs2/incore.h > @@ -621,6 +621,7 @@ struct gfs2_sbd { > u32 sd_hash_bsize_shift; > u32 sd_hash_ptrs; /* Number of pointers in a hash block */ > u32 sd_qc_per_block; > + u32 sd_blocks_per_bitmap; > u32 sd_max_dirres; /* Max blocks needed to add a directory entry */ > u32 sd_max_height; /* Max height of a file's metadata tree */ > u64 sd_heightsize[GFS2_MAX_META_HEIGHT + 1]; > diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c > index e443966..0e3554e 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 */ > > diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c > index 38fe18f..669b89b 100644 > --- a/fs/gfs2/rgrp.c > +++ b/fs/gfs2/rgrp.c > @@ -251,22 +251,25 @@ static u32 gfs2_bitfit(const u8 *buf, const unsigned int len, > static int gfs2_rbm_from_block(struct gfs2_rbm *rbm, u64 block) > { > u64 rblock = block - rbm->rgd->rd_data0; > - u32 goal = (u32)rblock; > - int x; > + u32 x; > > if (WARN_ON_ONCE(rblock > UINT_MAX)) > return -EINVAL; > if (block >= rbm->rgd->rd_data0 + rbm->rgd->rd_data) > return -E2BIG; > > - for (x = 0; x < rbm->rgd->rd_length; x++) { > - rbm->bi = rbm->rgd->rd_bits + x; > - if (goal < (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY) { > - rbm->offset = goal - (rbm->bi->bi_start * GFS2_NBBY); > - break; > - } > - } > + rbm->bi = rbm->rgd->rd_bits; > + rbm->offset = (u32)(rblock); > + /* Check if the block is within the first block */ > + if (rbm->offset < (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY) > + return 0; > > + /* Adjust for the size diff between gfs2_meta_header and gfs2_rgrp */ > + rbm->offset += (sizeof(struct gfs2_rgrp) - > + sizeof(struct gfs2_meta_header)) * GFS2_NBBY; > + x = rbm->offset / rbm->rgd->rd_sbd->sd_blocks_per_bitmap; > + rbm->offset -= x * rbm->rgd->rd_sbd->sd_blocks_per_bitmap; > + rbm->bi += x; > return 0; > } > >