On Thu, Oct 10, 2019 at 08:21:34AM -0700, Minchan Kim wrote: > From: Minchan Kim <minchan@xxxxxxxxxx> > > If block device supports rw_page operation, it doesn't submit bio > so annotation in submit_bio for refault stall doesn't work. > It happens with zram in android, especially swap read path which > could consume CPU cycle for decompress. It is also a problem for > zswap which uses frontswap. > > Annotate swap_readpage() to account the synchronous IO overhead > to prevent underreport memory pressure. > > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Can you please add a comment to the caller? Lifted from submit_bio(): /* * Count submission time as memory stall. When the device is * congested, or the submitting cgroup IO-throttled, * submission can be a significant part of overall IO time. */
