> There are stressful update of cluster allocation bitmap when using dirsync > mount option which is doing sync buffer on every cluster bit clearing. > This could result in performance degradation when deleting big size file. > Fix to update only when the bitmap buffer index is changed would make less > disk access, improving performance especially for truncate operation. > > Testing with Samsung 256GB sdcard, mounted with dirsync option (mount -t > exfat /dev/block/mmcblk0p1 /temp/mount -o dirsync) > > Remove 4GB file, blktrace result. > [Before] : 39 secs. > Total (blktrace): > Reads Queued: 0, 0KiB Writes Queued: 32775, 16387KiB > Read Dispatches: 0, 0KiB Write Dispatches: 32775, 16387KiB > Reads Requeued: 0 Writes Requeued: 0 > Reads Completed: 0, 0KiB Writes Completed: 32775, 16387KiB > Read Merges: 0, 0KiB Write Merges: 0, 0KiB > IO unplugs: 2 Timer unplugs: 0 > > [After] : 1 sec. > Total (blktrace): > Reads Queued: 0, 0KiB Writes Queued: 13, 6KiB > Read Dispatches: 0, 0KiB Write Dispatches: 13, 6KiB > Reads Requeued: 0 Writes Requeued: 0 > Reads Completed: 0, 0KiB Writes Completed: 13, 6KiB > Read Merges: 0, 0KiB Write Merges: 0, 0KiB > IO unplugs: 1 Timer unplugs: 0 > > Signed-off-by: Hyeongseok Kim <hyeongseok@xxxxxxxxx> Looks good. Thanks for your work! Acked-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
