The patch titled Subject: mm: avoid swapping out with swappiness==0 has been added to the -mm tree. Its filename is mm-avoid-swapping-out-with-swappiness==0.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Satoru Moriya <satoru.moriya@xxxxxxx> Subject: mm: avoid swapping out with swappiness==0 Sometimes we'd like to avoid swapping out anonymous memory in particular, avoid swapping out pages of important process or process groups while there is a reasonable amount of pagecache on RAM so that we can satisfy our customers' requirements. OTOH, we can control how aggressive the kernel will swap memory pages with /proc/sys/vm/swappiness for global and /sys/fs/cgroup/memory/memory.swappiness for each memcg. But with current reclaim implementation, the kernel may swap out even if we set swappiness=0 and there is pagecache in RAM. This patch changes the behavior with swappiness==0. If we set swappiness==0, the kernel does not swap out completely (for global reclaim until the amount of free pages and filebacked pages in a zone has been reduced to something very very small (nr_free + nr_filebacked < high watermark)). Signed-off-by: Satoru Moriya <satoru.moriya@xxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff -puN mm/vmscan.c~mm-avoid-swapping-out-with-swappiness==0 mm/vmscan.c --- a/mm/vmscan.c~mm-avoid-swapping-out-with-swappiness==0 +++ a/mm/vmscan.c @@ -1761,10 +1761,10 @@ static void get_scan_count(struct mem_cg * proportional to the fraction of recently scanned pages on * each list that were recently referenced and in active use. */ - ap = (anon_prio + 1) * (reclaim_stat->recent_scanned[0] + 1); + ap = anon_prio * (reclaim_stat->recent_scanned[0] + 1); ap /= reclaim_stat->recent_rotated[0] + 1; - fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1); + fp = file_prio * (reclaim_stat->recent_scanned[1] + 1); fp /= reclaim_stat->recent_rotated[1] + 1; spin_unlock_irq(&mz->zone->lru_lock); @@ -1777,7 +1777,7 @@ out: unsigned long scan; scan = zone_nr_lru_pages(mz, lru); - if (priority || noswap) { + if (priority || noswap || !vmscan_swappiness(mz, sc)) { scan >>= priority; if (!scan && force_scan) scan = SWAP_CLUSTER_MAX; _ Subject: Subject: mm: avoid swapping out with swappiness==0 Patches currently in -mm which might be from satoru.moriya@xxxxxxx are linux-next.patch mm-avoid-swapping-out-with-swappiness==0.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html