From f1fd1067ece574ab56e4a70878b9a5a1ed4c3c42 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 18 Jan 2006 17:42:30 -0800 Subject: [PATCH] [PATCH] Zone reclaim: resurrect may_swap Zone reclaim has a huge impact on NUMA performance (f.e. our maximum throughput with XFS is raised from 4GB to 6GB/sec / page cache contamination of numa nodes destroys locality if one just does a large copy operation which results in performance dropping for good until reboot). This patch: Resurrect may_swap in struct scan_control Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/vmscan.c b/mm/vmscan.c index 827bf674577..e5117b6897a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -71,6 +71,9 @@ struct scan_control { int may_writepage; + /* Can pages be swapped as part of reclaim? */ + int may_swap; + /* This context's SWAP_CLUSTER_MAX. If freeing memory for * suspend, we effectively ignore SWAP_CLUSTER_MAX. * In this context, it doesn't matter that we scan the @@ -458,6 +461,8 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc) * Try to allocate it some swap space here. */ if (PageAnon(page) && !PageSwapCache(page)) { + if (!sc->may_swap) + goto keep_locked; if (!add_to_swap(page, GFP_ATOMIC)) goto activate_locked; } @@ -1166,6 +1171,7 @@ int try_to_free_pages(struct zone **zones, gfp_t gfp_mask) sc.gfp_mask = gfp_mask; sc.may_writepage = 0; + sc.may_swap = 1; inc_page_state(allocstall); @@ -1268,6 +1274,7 @@ loop_again: total_reclaimed = 0; sc.gfp_mask = GFP_KERNEL; sc.may_writepage = 0; + sc.may_swap = 1; sc.nr_mapped = read_page_state(nr_mapped); inc_page_state(pageoutrun); -- 2.41.1