Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756492Ab3IYX1C (ORCPT ); Wed, 25 Sep 2013 19:27:02 -0400 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:33745 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756473Ab3IYX07 (ORCPT ); Wed, 25 Sep 2013 19:26:59 -0400 From: "Srivatsa S. Bhat" Subject: [RFC PATCH v4 39/40] mm: Add intelligence in kmempowerd to ignore regions unsuitable for evacuation To: akpm@linux-foundation.org, mgorman@suse.de, dave@sr71.net, hannes@cmpxchg.org, tony.luck@intel.com, matthew.garrett@nebula.com, riel@redhat.com, arjan@linux.intel.com, srinivas.pandruvada@linux.intel.com, willy@linux.intel.com, kamezawa.hiroyu@jp.fujitsu.com, lenb@kernel.org, rjw@sisk.pl Cc: gargankita@gmail.com, paulmck@linux.vnet.ibm.com, svaidy@linux.vnet.ibm.com, andi@firstfloor.org, isimatu.yasuaki@jp.fujitsu.com, santosh.shilimkar@ti.com, kosaki.motohiro@gmail.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Thu, 26 Sep 2013 04:52:42 +0530 Message-ID: <20130925232240.26184.54998.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> References: <20130925231250.26184.31438.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13092523-1618-0000-0000-000004B0A2BB Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3105 Lines: 95 Enhance kmempowerd to determine situations where evacuating a region would prove to be too costly or counter-productive, and ignore those regions for region evacuation. For example, if the region has a significant number of used pages (say more than 32), then evacuation will involve more work and might not be justifiable. Also, compacting region 0 would be pointless, since that is the target of all our compaction runs. Add these checks in the region-evacuator. Signed-off-by: Srivatsa S. Bhat --- include/linux/mmzone.h | 2 ++ mm/compaction.c | 25 +++++++++++++++++++++++-- mm/internal.h | 2 ++ 3 files changed, 27 insertions(+), 2 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 257afdf..f383cc8d4 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -84,6 +84,8 @@ static inline int get_pageblock_migratetype(struct page *page) return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end); } +#define MAX_MEMPWR_MIGRATE_PAGES 32 + struct mem_region_list { struct list_head *page_block; unsigned long nr_free; diff --git a/mm/compaction.c b/mm/compaction.c index b56be89..41585b0 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1297,9 +1297,26 @@ void queue_mempower_work(struct pglist_data *pgdat, struct zone *zone, queue_kthread_work(&pgdat->mempower_worker, &mpwork->work); } +int should_evacuate_region(struct zone *z, struct zone_mem_region *region) +{ + unsigned long pages_in_use; + + /* Don't try to evacuate region 0, since its the target of migration */ + if (region == z->zone_regions) + return 0; + + pages_in_use = region->present_pages - region->nr_free; + + if (pages_in_use > 0 && pages_in_use <= MAX_MEMPWR_MIGRATE_PAGES) + return 1; + + return 0; +} + static void kmempowerd(struct kthread_work *work) { struct mempower_work *mpwork; + struct zone_mem_region *zmr; struct zone *zone; unsigned long flags; int region_id; @@ -1315,8 +1332,12 @@ repeat: if (bitmap_empty(mpwork_mask, nr_zone_region_bits)) return; - for_each_set_bit(region_id, mpwork_mask, nr_zone_region_bits) - evacuate_mem_region(zone, &zone->zone_regions[region_id]); + for_each_set_bit(region_id, mpwork_mask, nr_zone_region_bits) { + zmr = &zone->zone_regions[region_id]; + + if (should_evacuate_region(zone, zmr)) + evacuate_mem_region(zone, zmr); + } spin_lock_irqsave(&mpwork->lock, flags); diff --git a/mm/internal.h b/mm/internal.h index 3fbc9f6..5b4658c 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -184,6 +184,8 @@ int compact_range(struct compact_control *cc, struct aggression_control *ac, void queue_mempower_work(struct pglist_data *pgdat, struct zone *zone, int region_id); +int should_evacuate_region(struct zone *z, struct zone_mem_region *region); + #endif /* -- 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/