diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 63 |
1 files changed, 47 insertions, 16 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5e92698..cfd565db 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1380,16 +1380,11 @@ void split_page(struct page *page, unsigned int order) } /* - * Similar to split_page except the page is already free. As this is only - * being used for migration, the migratetype of the block also changes. - * As this is called with interrupts disabled, the caller is responsible - * for calling arch_alloc_page() and kernel_map_page() after interrupts - * are enabled. - * - * Note: this is probably too low level an operation for use in drivers. - * Please consult with lkml before using this in your driver. + * Similar to the split_page family of functions except that the page + * required at the given order and being isolated now to prevent races + * with parallel allocators */ -int split_free_page(struct page *page) +int capture_free_page(struct page *page, int alloc_order, int migratetype) { unsigned int order; unsigned long watermark; @@ -1411,10 +1406,11 @@ int split_free_page(struct page *page) rmv_page_order(page); __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order)); - /* Split into individual pages */ - set_page_refcounted(page); - split_page(page, order); + if (alloc_order != order) + expand(zone, page, alloc_order, order, + &zone->free_area[order], migratetype); + /* Set the pageblock if the captured page is at least a pageblock */ if (order >= pageblock_order - 1) { struct page *endpage = page + (1 << order) - 1; for (; page < endpage; page += pageblock_nr_pages) { @@ -1425,7 +1421,35 @@ int split_free_page(struct page *page) } } - return 1 << order; + return 1UL << order; +} + +/* + * Similar to split_page except the page is already free. As this is only + * being used for migration, the migratetype of the block also changes. + * As this is called with interrupts disabled, the caller is responsible + * for calling arch_alloc_page() and kernel_map_page() after interrupts + * are enabled. + * + * Note: this is probably too low level an operation for use in drivers. + * Please consult with lkml before using this in your driver. + */ +int split_free_page(struct page *page) +{ + unsigned int order; + int nr_pages; + + BUG_ON(!PageBuddy(page)); + order = page_order(page); + + nr_pages = capture_free_page(page, order, 0); + if (!nr_pages) + return 0; + + /* Split into individual pages */ + set_page_refcounted(page); + split_page(page, order); + return nr_pages; } /* @@ -2105,7 +2129,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, bool *contended_compaction, bool *deferred_compaction, unsigned long *did_some_progress) { - struct page *page; + struct page *page = NULL; if (!order) return NULL; @@ -2118,10 +2142,16 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, current->flags |= PF_MEMALLOC; *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask, nodemask, sync_migration, - contended_compaction); + contended_compaction, &page); current->flags &= ~PF_MEMALLOC; - if (*did_some_progress != COMPACT_SKIPPED) { + /* If compaction captured a page, prep and use it */ + if (page) { + prep_new_page(page, order, gfp_mask); + goto got_page; + } + + if (*did_some_progress != COMPACT_SKIPPED) { /* Page migration frees to the PCP lists but we want merging */ drain_pages(get_cpu()); put_cpu(); @@ -2131,6 +2161,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, alloc_flags & ~ALLOC_NO_WATERMARKS, preferred_zone, migratetype); if (page) { +got_page: preferred_zone->compact_considered = 0; preferred_zone->compact_defer_shift = 0; if (order >= preferred_zone->compact_order_failed) |