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. 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
