Hi, On Tue, 12 May 2009 10:39:48 +0900, Hisashi Hifumi wrote: > 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. > > # 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 --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 <[email protected]> > > diff -Nrup linux-2.6.30-rc5.org/fs/nilfs2/inode.c > linux-2.6.30-rc5.nilfs/fs/nilfs2/inode.c > --- linux-2.6.30-rc5.org/fs/nilfs2/inode.c 2009-05-11 10:07:15.000000000 > +0900 > +++ linux-2.6.30-rc5.nilfs/fs/nilfs2/inode.c 2009-05-12 10:22:50.000000000 > +0900 > @@ -249,6 +249,7 @@ struct address_space_operations nilfs_ao > /* .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)
Thanks for adding aops->is_partially_uptodate support to nilfs2 and for evaluating the effect. I'll queue this in the branch for 2.6.31-rc1. Thanks, Ryusuke Konishi _______________________________________________ users mailing list [email protected] https://www.nilfs.org/mailman/listinfo/users
