On 06/18/13 23:50, Dave Chinner wrote:
From: Dave Chinner<dchinner@xxxxxxxxxx> I was running some tests on bulkstat on CRC enabled filesystems when I noticed that all the IO being issued was 8k in size, regardless of the fact taht we are issuing sequential 8k buffers for inodes clusters. The IO size shoul dbe 16k for 256 byte inodes, and 32k for 512 byte inodes, but this wasn't happening. blktrace showed that there was an explict plug and unplug happening around each readahead IO from _xfs_buf_ioapply, and the unplug was causing the IO to be issued immediately. Hence no opportunity was being given to the elevator to merge adjacent readahead requests and dispatch them as a single IO. Add plugging around the inode chunk readahead dispatch loop tin bulkstat to ensure that we don't unplug the queue between adjacent inode buffer readahead IOs and so we get fewer, larger IO requests hitting the storage subsystemi for bulkstat. Signed-off-by: Dave Chinner<dchinner@xxxxxxxxxx> ---
Looks good. Reviewed-by: Mark Tinguely <tinguely@xxxxxxx> _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
