> Now, vmscan pageout() is one of IO throuput degression source. > Some IO workload makes very much order-0 allocation and reclaim > and pageout's 4K IOs are making annoying lots seeks. > > At least, kswapd can avoid such pageout() because kswapd don't > need to consider OOM-Killer situation. that's no risk. I've found one bug in this patch myself. flusher thread don't pageout anon pages. then, we need PageAnon() check ;) > > Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> > --- > mm/vmscan.c | 7 +++++++ > 1 files changed, 7 insertions(+), 0 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 3ff3311..d392a50 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -614,6 +614,13 @@ static enum page_references page_check_references(struct page *page, > if (referenced_page) > return PAGEREF_RECLAIM_CLEAN; > > + /* > + * Delegate pageout IO to flusher thread. They can make more > + * effective IO pattern. > + */ > + if (current_is_kswapd()) > + return PAGEREF_RECLAIM_CLEAN; > + > return PAGEREF_RECLAIM; > } > > -- > 1.6.5.2 > > > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
