From 258ef67e246fd548e7ad91c23004ad157c03cce5 Mon Sep 17 00:00:00 2001 From: Hisashi Hifumi Date: Wed, 13 May 2009 11:19:40 +0900 Subject: NILFS2: Pagecache usage optimization on NILFS2 Hi, I introduced "is_partially_uptodate" aops for NILFS2. 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. 1 --file-block-size=8K --file-total-size=2G --file-test-mode=rndrw --file-fsync-freq=0 --fil e-rw-ratio=1 run -2.6.30-rc5 Test execution summary: total time: 151.2907s total number of events: 200000 total time taken by event execution: 2409.8387 per-request statistics: min: 0.0000s avg: 0.0120s max: 0.9306s approx. 95 percentile: 0.0439s Threads fairness: events (avg/stddev): 12500.0000/238.52 execution time (avg/stddev): 150.6149/0.01 -2.6.30-rc5-patched Test execution summary: total time: 140.8828s total number of events: 200000 total time taken by event execution: 2240.8577 per-request statistics: min: 0.0000s avg: 0.0112s max: 0.8750s approx. 95 percentile: 0.0418s Threads fairness: events (avg/stddev): 12500.0000/218.43 execution time (avg/stddev): 140.0536/0.01 arch: ia64 pagesize: 16k Thanks. Signed-off-by: Hisashi Hifumi Signed-off-by: Ryusuke Konishi --- fs/nilfs2/inode.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs') diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 49ab4a49bb4..3f70eedc0de 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -249,6 +249,7 @@ struct address_space_operations nilfs_aops = { /* .releasepage = nilfs_releasepage, */ .invalidatepage = block_invalidatepage, .direct_IO = nilfs_direct_IO, + .is_partially_uptodate = block_is_partially_uptodate, }; struct inode *nilfs_new_inode(struct inode *dir, int mode) -- cgit v1.2.3-70-g09d2