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 <[EMAIL PROTECTED]> --- page_alloc.c | 28 +++++++++++++++++++++++++++- 1 files changed, 27 insertions(+), 1 deletion(-) diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.20-mm2-006_configurable/mm/page_alloc.c linux-2.6.20-mm2-007_drainpercpu/mm/page_alloc.c --- linux-2.6.20-mm2-006_configurable/mm/page_alloc.c 2007-02-20 18:33:41.000000000 +0000 +++ linux-2.6.20-mm2-007_drainpercpu/mm/page_alloc.c 2007-02-20 18:35:52.000000000 +0000 @@ -916,7 +916,9 @@ void mark_free_pages(struct zone *zone) spin_unlock_irqrestore(&zone->lock, flags); } +#endif /* CONFIG_PM */ +#if defined(CONFIG_PM) || defined(CONFIG_PAGE_GROUP_BY_MOBILITY) /* * Spill all of this CPU's per-cpu pages back into the buddy allocator. */ @@ -928,7 +930,28 @@ void drain_local_pages(void) __drain_pages(smp_processor_id()); local_irq_restore(flags); } -#endif /* CONFIG_PM */ + +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_PM || CONFIG_PAGE_GROUP_BY_MOBILITY */ /* * Free a 0-order page @@ -1557,6 +1580,9 @@ 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); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/