Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754396AbbKYIKq (ORCPT ); Wed, 25 Nov 2015 03:10:46 -0500 Received: from LGEAMRELO13.lge.com ([156.147.23.53]:39810 "EHLO lgeamrelo13.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754210AbbKYIKo (ORCPT ); Wed, 25 Nov 2015 03:10:44 -0500 X-Original-SENDERIP: 156.147.1.151 X-Original-MAILFROM: iamjoonsoo.kim@lge.com X-Original-SENDERIP: 10.177.222.138 X-Original-MAILFROM: iamjoonsoo.kim@lge.com Date: Wed, 25 Nov 2015 17:11:10 +0900 From: Joonsoo Kim To: Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Minchan Kim , Sasha Levin , "Kirill A. Shutemov" , Mel Gorman , Michal Hocko Subject: Re: [PATCH v2 2/9] mm, page_owner: print symbolic migratetype of both page and pageblock Message-ID: <20151125081110.GA10494@js1304-P5Q-DELUXE> References: <1448368581-6923-1-git-send-email-vbabka@suse.cz> <1448368581-6923-3-git-send-email-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1448368581-6923-3-git-send-email-vbabka@suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3887 Lines: 97 On Tue, Nov 24, 2015 at 01:36:14PM +0100, Vlastimil Babka wrote: > The information in /sys/kernel/debug/page_owner includes the migratetype of > the pageblock the page belongs to. This is also checked against the page's > migratetype (as declared by gfp_flags during its allocation), and the page is > reported as Fallback if its migratetype differs from the pageblock's one. > > This is somewhat misleading because in fact fallback allocation is not the only > reason why these two can differ. It also doesn't direcly provide the page's > migratetype, although it's possible to derive that from the gfp_flags. > > It's arguably better to print both page and pageblock's migratetype and leave > the interpretation to the consumer than to suggest fallback allocation as the > only possible reason. While at it, we can print the migratetypes as string > the same way as /proc/pagetypeinfo does, as some of the numeric values depend > on kernel configuration. For that, this patch moves the migratetype_names > array from #ifdef CONFIG_PROC_FS part of mm/vmstat.c to mm/page_alloc.c and > exports it. > > Example page_owner entry after the patch: > > Page allocated via order 0, mask 0x2420848 > PFN 512 type Reclaimable Block 1 type Reclaimable Flags R LA > [] __alloc_pages_nodemask+0x15a/0xa30 > [] alloc_pages_current+0x88/0x120 > [] __page_cache_alloc+0xe6/0x120 > [] pagecache_get_page+0x56/0x200 > [] __getblk_slow+0xd2/0x2b0 > [] __getblk_gfp+0x40/0x50 > [] __breadahead+0x17/0x50 > [] __ext4_get_inode_loc+0x397/0x3e0 [ext4] > > Signed-off-by: Vlastimil Babka > --- > include/linux/mmzone.h | 3 +++ > mm/page_alloc.c | 13 +++++++++++++ > mm/page_owner.c | 6 +++--- > mm/vmstat.c | 13 ------------- > 4 files changed, 19 insertions(+), 16 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 3b6fb71..2bfad18 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -63,6 +63,9 @@ enum { > MIGRATE_TYPES > }; > > +/* In mm/page_alloc.c; keep in sync also with show_migration_types() there */ > +extern char * const migratetype_names[MIGRATE_TYPES]; > + > #ifdef CONFIG_CMA > # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA) > #else > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 35ab351..61a023a 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -229,6 +229,19 @@ static char * const zone_names[MAX_NR_ZONES] = { > #endif > }; > > +char * const migratetype_names[MIGRATE_TYPES] = { > + "Unmovable", > + "Movable", > + "Reclaimable", > + "HighAtomic", > +#ifdef CONFIG_CMA > + "CMA", > +#endif > +#ifdef CONFIG_MEMORY_ISOLATION > + "Isolate", > +#endif > +}; > + > compound_page_dtor * const compound_page_dtors[] = { > NULL, > free_compound_page, > diff --git a/mm/page_owner.c b/mm/page_owner.c > index 983c3a1..f35826e 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -110,11 +110,11 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, > pageblock_mt = get_pfnblock_migratetype(page, pfn); > page_mt = gfpflags_to_migratetype(page_ext->gfp_mask); > ret += snprintf(kbuf + ret, count - ret, > - "PFN %lu Block %lu type %d %s Flags %s%s%s%s%s%s%s%s%s%s%s%s\n", > + "PFN %lu type %s Block %lu type %s Flags %s%s%s%s%s%s%s%s%s%s%s%s\n", How about generalizing dump_flag_names() more and using it here? This output is neat than dump_flag_names() but not complete. Thanks. -- 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/