linux/fs/xfs/linux-2.6
Hisashi Hifumi bddaafa11a xfs: pagecache usage optimization
Hi.

I introduced "is_partially_uptodate" aops for XFS.

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=4 --max-requests=100000 --test=fileio --file-num=1 \
--file-block-size=8K --file-total-size=1G --file-test-mode=rndrw \
--file-fsync-freq=0 --file-rw-ratio=0.5 run

-2.6.29-rc6
Test execution summary:
    total time:                          123.8645s
    total number of events:              100000
    total time taken by event execution: 442.4994
    per-request statistics:
         min:                            0.0000s
         avg:                            0.0044s
         max:                            0.3387s
         approx.  95 percentile:         0.0118s

-2.6.29-rc6-patched
Test execution summary:
    total time:                          108.0757s
    total number of events:              100000
    total time taken by event execution: 417.7505
    per-request statistics:
         min:                            0.0000s
         avg:                            0.0042s
         max:                            0.3217s
         approx.  95 percentile:         0.0118s

arch: ia64
pagesize: 16k
blocksize: 4k

Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
2009-03-29 09:53:38 +02:00
..
kmem.c [XFS] kmem_free and kmem_realloc to use const void * 2008-07-28 16:58:43 +10:00
kmem.h [XFS] kmem_free and kmem_realloc to use const void * 2008-07-28 16:58:43 +10:00
mrlock.h [XFS] shrink mrlock_t 2008-04-29 15:54:02 +10:00
sv.h remove dead code from sv_t implementation 2008-12-04 15:39:21 +11:00
time.h
xfs_aops.c xfs: pagecache usage optimization 2009-03-29 09:53:38 +02:00
xfs_aops.h [XFS] Remove several unused typedefs. 2009-01-09 15:46:16 +11:00
xfs_buf.c xfs: only issues a cache flush on unmount if barriers are enabled 2009-03-04 07:31:55 -06:00
xfs_buf.h xfs: only issues a cache flush on unmount if barriers are enabled 2009-03-04 07:31:55 -06:00
xfs_cred.h [XFS] Fix merge failures 2008-12-29 16:47:18 +11:00
xfs_dmapi_priv.h
xfs_export.c [XFS] pass XFS_IGET_BULKSTAT to xfs_iget for handle operations 2009-01-09 15:17:17 +11:00
xfs_export.h
xfs_file.c [XFS] Use the incore inode size in xfs_file_readdir() 2008-12-22 17:50:56 +11:00
xfs_fs_subr.c [XFS] fix error inversion problems with data flushing 2008-12-01 11:11:10 +11:00
xfs_fs_subr.h
xfs_globals.c [XFS] remove restricted chown parameter from xfs linux 2008-10-30 18:30:48 +11:00
xfs_globals.h CRED: Separate task security context from task_struct 2008-11-14 10:39:16 +11:00
xfs_ioctl32.c xfs: use mnt_want_write in compat_attrmulti ioctl 2009-01-19 02:03:03 +01:00
xfs_ioctl32.h [XFS] fix compile on 32 bit systems 2008-12-04 13:07:29 +11:00
xfs_ioctl.c xfs: include header files for prototypes 2009-03-06 17:21:16 -06:00
xfs_ioctl.h xfs: fix dentry aliasing issues in open_by_handle 2009-01-19 02:02:57 +01:00
xfs_iops.c xfs: kill ino64 mount option 2009-03-29 09:51:08 +02:00
xfs_iops.h [XFS] add a FMODE flag to make XFS invisible I/O less hacky 2008-12-11 13:14:41 +11:00
xfs_linux.h xfs: kill mutex_t typedef 2009-03-29 09:51:00 +02:00
xfs_lrw.c [XFS] Fix race in xfs_write() between direct and buffered I/O with DMAPI 2008-12-24 14:07:32 +11:00
xfs_lrw.h [XFS] remove sendfile leftovers 2008-04-29 16:08:14 +10:00
xfs_quotaops.c xfs: get rid of indirections in the quotaops implementation 2009-02-09 08:47:34 +01:00
xfs_stats.c [XFS] fix spurious gcc warnings 2008-12-01 11:07:37 +11:00
xfs_stats.h [XFS] add new btree statistics 2008-10-30 16:55:03 +11:00
xfs_super.c xfs: kill ino64 mount option 2009-03-29 09:51:08 +02:00
xfs_super.h xfs: get rid of indirections in the quotaops implementation 2009-02-09 08:47:34 +01:00
xfs_sync.c [XFS] Warn on transaction in flight on read-only remount 2009-01-27 13:37:24 -06:00
xfs_sync.h xfs: get rid of indirections in the quotaops implementation 2009-02-09 08:47:34 +01:00
xfs_sysctl.c [XFS] remove restricted chown parameter from xfs linux 2008-10-30 18:30:48 +11:00
xfs_sysctl.h [XFS] remove restricted chown parameter from xfs linux 2008-10-30 18:30:48 +11:00
xfs_version.h
xfs_vnode.h xfs: kill VN_BAD 2009-03-16 08:25:25 +01:00
xfs_xattr.c [XFS] Remove vn_revalidate calls in xfs. 2008-07-28 16:59:39 +10:00