commit: 2b6c26a0a62cc0bab0ad487533d5581d7c293fef From: Jeff Layton <[email protected]> Date: Fri, 25 Mar 2011 16:25:57 -0400 Subject: [PATCH] cifs: set ra_pages in backing_dev_info
Commit 522440ed made cifs set backing_dev_info on the mapping attached to new inodes. This change caused a fairly significant read performance regression, as cifs started doing page-sized reads exclusively. By virtue of the fact that they're allocated as part of cifs_sb_info by kzalloc, the ra_pages on cifs BDIs get set to 0, which prevents any readahead. This forces the normal read codepaths to use readpage instead of readpages causing a four-fold increase in the number of read calls with the default rsize. Fix it by setting ra_pages in the BDI to the same value as that in the default_backing_dev_info. Fixes https://bugzilla.kernel.org/show_bug.cgi?id=31662 Cc: [email protected] Reported-and-Tested-by: Till <[email protected]> Signed-off-by: Jeff Layton <[email protected]> Signed-off-by: Steve French <[email protected]> --- fs/cifs/cifsfs.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 0e0cc60..e3352a1 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -130,6 +130,7 @@ cifs_read_super(struct super_block *sb, void *data, kfree(cifs_sb); return rc; } + cifs_sb->bdi.ra_pages = default_backing_dev_info.ra_pages; #ifdef CONFIG_CIFS_DFS_UPCALL /* copy mount params to sb for use in submounts */ _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
