diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page-writeback.c | 5 | ||||
| -rw-r--r-- | mm/page_alloc.c | 19 |
2 files changed, 22 insertions, 2 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index c081bf62202..9ab6de82d8e 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -157,7 +157,7 @@ static unsigned long highmem_dirtyable_memory(unsigned long total) &NODE_DATA(node)->node_zones[ZONE_HIGHMEM]; x += zone_page_state(z, NR_FREE_PAGES) + - zone_reclaimable_pages(z); + zone_reclaimable_pages(z) - z->dirty_balance_reserve; } /* * Make sure that the number of highmem pages is never larger @@ -181,7 +181,8 @@ static unsigned long determine_dirtyable_memory(void) { unsigned long x; - x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages(); + x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages() - + dirty_balance_reserve; if (!vm_highmem_is_dirtyable) x -= highmem_dirtyable_memory(x); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 93baebcc06f..2cb9eb71e28 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -97,6 +97,14 @@ EXPORT_SYMBOL(node_states); unsigned long totalram_pages __read_mostly; unsigned long totalreserve_pages __read_mostly; +/* + * When calculating the number of globally allowed dirty pages, there + * is a certain number of per-zone reserves that should not be + * considered dirtyable memory. This is the sum of those reserves + * over all existing zones that contribute dirtyable memory. + */ +unsigned long dirty_balance_reserve __read_mostly; + int percpu_pagelist_fraction; gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; @@ -4822,8 +4830,19 @@ static void calculate_totalreserve_pages(void) if (max > zone->present_pages) max = zone->present_pages; reserve_pages += max; + /* + * Lowmem reserves are not available to + * GFP_HIGHUSER page cache allocations and + * kswapd tries to balance zones to their high + * watermark. As a result, neither should be + * regarded as dirtyable memory, to prevent a + * situation where reclaim has to clean pages + * in order to balance the zones. + */ + zone->dirty_balance_reserve = max; } } + dirty_balance_reserve = reserve_pages; totalreserve_pages = reserve_pages; } |