From f7b7fd8f3ebbb2810d6893295aa984acd0fd30db Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Mon, 28 Nov 2005 13:44:07 -0800 Subject: [PATCH] temporarily disable swap token on memory pressure Some users (hi Zwane) have seen a problem when running a workload that eats nearly all of physical memory - th system does an OOM kill, even when there is still a lot of swap free. The problem appears to be a very big task that is holding the swap token, and the VM has a very hard time finding any other page in the system that is swappable. Instead of ignoring the swap token when sc->priority reaches 0, we could simply take the swap token away from the memory hog and make sure we don't give it back to the memory hog for a few seconds. This patch resolves the problem Zwane ran into. Signed-off-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index 28130541270f..078cf920208a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -407,7 +407,7 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc) if (PageWriteback(page)) goto keep_locked; - referenced = page_referenced(page, 1, sc->priority <= 0); + referenced = page_referenced(page, 1); /* In active use or really unfreeable? Activate it. */ if (referenced && page_mapping_inuse(page)) goto activate_locked; @@ -756,7 +756,7 @@ refill_inactive_zone(struct zone *zone, struct scan_control *sc) if (page_mapped(page)) { if (!reclaim_mapped || (total_swap_pages == 0 && PageAnon(page)) || - page_referenced(page, 0, sc->priority <= 0)) { + page_referenced(page, 0)) { list_add(&page->lru, &l_active); continue; } @@ -960,6 +960,8 @@ int try_to_free_pages(struct zone **zones, gfp_t gfp_mask) sc.nr_reclaimed = 0; sc.priority = priority; sc.swap_cluster_max = SWAP_CLUSTER_MAX; + if (!priority) + disable_swap_token(); shrink_caches(zones, &sc); shrink_slab(sc.nr_scanned, gfp_mask, lru_pages); if (reclaim_state) { @@ -1056,6 +1058,10 @@ loop_again: int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */ unsigned long lru_pages = 0; + /* The swap token gets in the way of swapout... */ + if (!priority) + disable_swap_token(); + all_zones_ok = 1; if (nr_pages == 0) { @@ -1360,6 +1366,7 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) sc.nr_reclaimed = 0; /* scan at the highest priority */ sc.priority = 0; + disable_swap_token(); if (nr_pages > SWAP_CLUSTER_MAX) sc.swap_cluster_max = nr_pages; -- cgit v1.2.3-55-g7522