On Mon, Aug 23, 2010 at 10:10:37PM +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@xxxxxxxxxx> > > During data integrity (WB_SYNC_ALL) writeback, wbc->nr_to_write will > go negative on inodes with more than 1024 dirty pages due to > implementation details of write_cache_pages(). Currently XFS will > abort page clustering in writeback once nr_to_write drops below > zero, and so for data integrity writeback we will do very > inefficient page at a time allocation and IO submission for inodes > with large numbers of dirty pages. > > Fix this by only aborting the page clustering code when > wbc->nr_to_write is negative and the sync mode is WB_SYNC_NONE. Looks okay, but I wonder why if we should remove the check entirely. We're clustering inside the same extent, and we already have a cap for the extent size. That means the additional I/O basically is for free and we really shouldn't let the writeback code restrict us here. Reviewed-by: Christoph Hellwig <hch@xxxxxx> _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
