From: Jeff Layton Date: Fri, 25 Mar 2011 20:25:57 +0000 (-0400) Subject: cifs: set ra_pages in backing_dev_info X-Git-Tag: v2.6.39-rc4~62^2~6 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2b6c26a0a62cc0bab0ad487533d5581d7c293fef;p=pandora-kernel.git 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: stable@kernel.org Reported-and-Tested-by: Till Signed-off-by: Jeff Layton Signed-off-by: Steve French --- Reading git-diff-tree failed