Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752758Ab3HVIoc (ORCPT ); Thu, 22 Aug 2013 04:44:32 -0400 Received: from lgeamrelo01.lge.com ([156.147.1.125]:55113 "EHLO LGEAMRELO01.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752186Ab3HVIoT (ORCPT ); Thu, 22 Aug 2013 04:44:19 -0400 X-AuditID: 9c93017d-b7cdfae0000026c0-4c-5215cf6206fa From: Joonsoo Kim To: Pekka Enberg Cc: Christoph Lameter , Andrew Morton , Joonsoo Kim , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim , Mel Gorman Subject: [PATCH 01/16] slab: correct pfmemalloc check Date: Thu, 22 Aug 2013 17:44:10 +0900 Message-Id: <1377161065-30552-2-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1377161065-30552-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1377161065-30552-1-git-send-email-iamjoonsoo.kim@lge.com> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1978 Lines: 56 We checked pfmemalloc by slab unit, not page unit. You can see this in is_slab_pfmemalloc(). So other pages don't need to be set/cleared pfmemalloc. And, therefore we should check pfmemalloc in page flag of first page, but current implementation don't do that. virt_to_head_page(obj) just return 'struct page' of that object, not one of first page, since the SLAB don't use __GFP_COMP when CONFIG_MMU. To get 'struct page' of first page, we first get a slab and try to get it via virt_to_head_page(slab->s_mem). Cc: Mel Gorman Signed-off-by: Joonsoo Kim diff --git a/mm/slab.c b/mm/slab.c index 8ccd296..d9eae39 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -930,7 +930,8 @@ static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, { if (unlikely(pfmemalloc_active)) { /* Some pfmemalloc slabs exist, check if this is one */ - struct page *page = virt_to_head_page(objp); + struct slab *slabp = virt_to_slab(objp); + struct page *page = virt_to_head_page(slabp->s_mem); if (PageSlabPfmemalloc(page)) set_obj_pfmemalloc(&objp); } @@ -1770,7 +1771,7 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) __SetPageSlab(page + i); if (page->pfmemalloc) - SetPageSlabPfmemalloc(page + i); + SetPageSlabPfmemalloc(page); } memcg_bind_pages(cachep, cachep->gfporder); @@ -1803,9 +1804,10 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr) else sub_zone_page_state(page_zone(page), NR_SLAB_UNRECLAIMABLE, nr_freed); + + __ClearPageSlabPfmemalloc(page); while (i--) { BUG_ON(!PageSlab(page)); - __ClearPageSlabPfmemalloc(page); __ClearPageSlab(page); page++; } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/