From e2c55dc87f4a398b9c4dcc702dbc23a07fe14e23 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 16 Oct 2007 01:25:50 -0700 Subject: [PATCH] Drain per-cpu lists when high-order allocations fail Per-cpu pages can accidentally cause fragmentation because they are free, but pinned pages in an otherwise contiguous block. When this patch is applied, the per-cpu caches are drained after the direct-reclaim is entered if the requested order is greater than 0. It simply reuses the code used by suspend and hotplug. Signed-off-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index fea1e3b56c..aa7e5d2f28 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -876,7 +876,9 @@ void mark_free_pages(struct zone *zone) } spin_unlock_irqrestore(&zone->lock, flags); } +#endif /* CONFIG_PM */ +#if defined(CONFIG_HIBERNATION) || defined(CONFIG_PAGE_GROUP_BY_MOBILITY) /* * Spill all of this CPU's per-cpu pages back into the buddy allocator. */ @@ -888,7 +890,28 @@ void drain_local_pages(void) __drain_pages(smp_processor_id()); local_irq_restore(flags); } -#endif /* CONFIG_HIBERNATION */ + +void smp_drain_local_pages(void *arg) +{ + drain_local_pages(); +} + +/* + * Spill all the per-cpu pages from all CPUs back into the buddy allocator + */ +void drain_all_local_pages(void) +{ + unsigned long flags; + + local_irq_save(flags); + __drain_pages(smp_processor_id()); + local_irq_restore(flags); + + smp_call_function(smp_drain_local_pages, NULL, 0, 1); +} +#else +void drain_all_local_pages(void) {} +#endif /* CONFIG_HIBERNATION || CONFIG_PAGE_GROUP_BY_MOBILITY */ /* * Free a 0-order page @@ -1480,6 +1503,9 @@ nofail_alloc: cond_resched(); + if (order != 0) + drain_all_local_pages(); + if (likely(did_some_progress)) { page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags); -- 2.39.2