Commit 229615def3f573fc448d20f62c6ec1bc9340cefb
Committed by
Steven Whitehouse
Steven Whitehouse
1 parent
02ab172159
Exists in
master
and in
39 other branches
GFS2: Pagecache usage optimization on GFS2
I introduced "is_partially_uptodate" aops for GFS2.
A page can have multiple buffers and even if a page is not uptodate, some buffers
can be uptodate on pagesize != blocksize environment.
This aops checks that all buffers which correspond to a part of a file
that we want to read are uptodate. If so, we do not have to issue actual
read IO to HDD even if a page is not uptodate because the portion we
want to read are uptodate.
"block_is_partially_uptodate" function is already used by ext2/3/4.
With the following patch random read/write mixed workloads or random read after
random write workloads can be optimized and we can get performance improvement.
I did a performance test using the sysbench.
#sysbench --num-threads=16 --max-requests=200000 --test=fileio --file-num=1
--file-block-size=8K --file-total-size=2G --file-test-mode=rndrw --file-fsync-freq=0
--file-rw-ratio=1 run
-2.6.29-rc6
Test execution summary:
total time: 202.6389s
total number of events: 200000
total time taken by event execution: 2580.0480
per-request statistics:
min: 0.0000s
avg: 0.0129s
max: 49.5852s
approx. 95 percentile: 0.0462s
-2.6.29-rc6-patched
Test execution summary:
total time: 177.8639s
total number of events: 200000
total time taken by event execution: 2419.0199
per-request statistics:
min: 0.0000s
avg: 0.0121s
max: 52.4306s
approx. 95 percentile: 0.0444s
arch: ia64
pagesize: 16k
blocksize: 4k
Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Showing 1 changed file with 3 additions and 0 deletions Side-by-side Diff
fs/gfs2/ops_address.c
| ... | ... | @@ -1096,6 +1096,7 @@ |
| 1096 | 1096 | .releasepage = gfs2_releasepage, |
| 1097 | 1097 | .direct_IO = gfs2_direct_IO, |
| 1098 | 1098 | .migratepage = buffer_migrate_page, |
| 1099 | + .is_partially_uptodate = block_is_partially_uptodate, | |
| 1099 | 1100 | }; |
| 1100 | 1101 | |
| 1101 | 1102 | static const struct address_space_operations gfs2_ordered_aops = { |
| ... | ... | @@ -1111,6 +1112,7 @@ |
| 1111 | 1112 | .releasepage = gfs2_releasepage, |
| 1112 | 1113 | .direct_IO = gfs2_direct_IO, |
| 1113 | 1114 | .migratepage = buffer_migrate_page, |
| 1115 | + .is_partially_uptodate = block_is_partially_uptodate, | |
| 1114 | 1116 | }; |
| 1115 | 1117 | |
| 1116 | 1118 | static const struct address_space_operations gfs2_jdata_aops = { |
| ... | ... | @@ -1125,6 +1127,7 @@ |
| 1125 | 1127 | .bmap = gfs2_bmap, |
| 1126 | 1128 | .invalidatepage = gfs2_invalidatepage, |
| 1127 | 1129 | .releasepage = gfs2_releasepage, |
| 1130 | + .is_partially_uptodate = block_is_partially_uptodate, | |
| 1128 | 1131 | }; |
| 1129 | 1132 | |
| 1130 | 1133 | void gfs2_set_aops(struct inode *inode) |