On Tue, Nov 22, 2011 at 01:34:25PM -0800, Greg KH wrote: > On Sat, Nov 19, 2011 at 01:13:40PM -0500, Christoph Hellwig wrote: > > There is no need to grab the i_mutex of the IO lock in exclusive > > mode if we don't need to invalidate the page cache. Taking these > > locks on every direct IO effective serialises them as taking the IO > > lock in exclusive mode has to wait for all shared holders to drop > > the lock. That only happens when IO is complete, so effective it > > prevents dispatch of concurrent direct IO reads to the same inode. > > > > Fix this by taking the IO lock shared to check the page cache state, > > and only then drop it and take the IO lock exclusively if there is > > work to be done. Hence for the normal direct IO case, no exclusive > > locking will occur. > > > > Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx> > > Tested-by: Joern Engel <joern@xxxxxxxxx> > > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > > Signed-off-by: Alex Elder <aelder@xxxxxxx> > > What is the git commit id that matches this patch in Linus's tree? Nevermind, I found it, 0c38a2512df272b14ef4238b476a2e4f70da1479, right? Next time, please include the git commit id of the patch in Linus's tree so I don't have to dig it out like I did for this series. thanks, greg k-h _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
