> > 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 <hyeongs...@gmail.com>
>
> Looks good.
> Thanks for your work!
>
> Acked-by: Sungjong Seo <sj1557....@samsung.com>
Applied. Thanks!
