diff options
| author | Jeff Layton <jlayton@redhat.com> | 2012-05-01 17:41:49 -0400 |
|---|---|---|
| committer | Steve French <sfrench@us.ibm.com> | 2012-05-01 22:27:54 -0500 |
| commit | 8f71465c19ffefbfd0da3c1f5dc172b4bce05e93 (patch) | |
| tree | c27bb25b91b148e5977ea29132dc98ccea89f725 /fs | |
| parent | 156d17905e783d057061b3b56a9b3befec064e47 (diff) | |
| download | linux-8f71465c19ffefbfd0da3c1f5dc172b4bce05e93.tar.bz2 | |
cifs: don't cap ra_pages at the same level as default_backing_dev_info
While testing, I've found that even when we are able to negotiate a
much larger rsize with the server, on-the-wire reads often end up being
capped at 128k because of ra_pages being capped at that level.
Lifting this restriction gave almost a twofold increase in sequential
read performance on my craptactular KVM test rig with a 1M rsize.
I think this is safe since the actual ra_pages that the VM requests
is run through max_sane_readahead() prior to submitting the I/O. Under
memory pressure we should end up with large readahead requests being
suppressed anyway.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/cifs/connect.c | 18 |
1 files changed, 1 insertions, 17 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index f4d381e331ce..6ce888b04dc8 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3614,22 +3614,6 @@ cifs_get_volume_info(char *mount_data, const char *devname) return volume_info; } -/* make sure ra_pages is a multiple of rsize */ -static inline unsigned int -cifs_ra_pages(struct cifs_sb_info *cifs_sb) -{ - unsigned int reads; - unsigned int rsize_pages = cifs_sb->rsize / PAGE_CACHE_SIZE; - - if (rsize_pages >= default_backing_dev_info.ra_pages) - return default_backing_dev_info.ra_pages; - else if (rsize_pages == 0) - return rsize_pages; - - reads = default_backing_dev_info.ra_pages / rsize_pages; - return reads * rsize_pages; -} - int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info) { @@ -3717,7 +3701,7 @@ try_mount_again: cifs_sb->rsize = cifs_negotiate_rsize(tcon, volume_info); /* tune readahead according to rsize */ - cifs_sb->bdi.ra_pages = cifs_ra_pages(cifs_sb); + cifs_sb->bdi.ra_pages = cifs_sb->rsize / PAGE_CACHE_SIZE; remote_path_check: #ifdef CONFIG_CIFS_DFS_UPCALL |