From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932144Ab2AXSYT (ORCPT ); Tue, 24 Jan 2012 13:24:19 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52388 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932125Ab2AXSYQ (ORCPT ); Tue, 24 Jan 2012 13:24:16 -0500 Date: Tue, 24 Jan 2012 13:21:36 -0500 From: Rik van Riel To: linux-mm@kvack.org Cc: lkml , Andrea Arcangeli , Mel Gorman , Johannes Weiner , Andrew Morton , Minchan Kim , KOSAKI Motohiro Subject: [PATCH v2 -mm 1/3] mm: reclaim at order 0 when compaction is enabled Message-ID: <20120124132136.3b765f0c@annuminas.surriel.com> In-Reply-To: <20120124131822.4dc03524@annuminas.surriel.com> References: <20120124131822.4dc03524@annuminas.surriel.com> Organization: Red Hat, Inc. Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When built with CONFIG_COMPACTION, kswapd does not try to free contiguous pages. Because it is not trying, it should also not test whether it succeeded, because that can result in continuous page reclaim, until a large fraction of memory is free and large fractions of the working set have been evicted. In shrink_inactive_list, we should not try to do higher order (out of LRU order) page isolation, unless we really are in lumpy reclaim mode. This gives all pages a good amount of time on the inactive list, giving the actively used pages the chance to get referenced and avoid eviction. Also remove a line of code that increments balanced right before exiting the function. Signed-off-by: Rik van Riel --- mm/vmscan.c | 29 ++++++++++++++++++++++------- 1 files changed, 22 insertions(+), 7 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 2880396..0398fab 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1512,6 +1512,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, unsigned long nr_writeback = 0; isolate_mode_t reclaim_mode = ISOLATE_INACTIVE; struct zone *zone = mz->zone; + int order = 0; while (unlikely(too_many_isolated(zone, file, sc))) { congestion_wait(BLK_RW_ASYNC, HZ/10); @@ -1522,8 +1523,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, } set_reclaim_mode(priority, sc, false); - if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM) + if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM) { reclaim_mode |= ISOLATE_ACTIVE; + order = sc->order; + } lru_add_drain(); @@ -1535,7 +1538,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, spin_lock_irq(&zone->lru_lock); nr_taken = isolate_lru_pages(nr_to_scan, mz, &page_list, - &nr_scanned, sc->order, + &nr_scanned, order, reclaim_mode, 0, file); if (global_reclaim(sc)) { zone->pages_scanned += nr_scanned; @@ -2754,7 +2757,7 @@ loop_again: */ for (i = 0; i <= end_zone; i++) { struct zone *zone = pgdat->node_zones + i; - int nr_slab; + int nr_slab, testorder; unsigned long balance_gap; if (!populated_zone(zone)) @@ -2783,11 +2786,25 @@ loop_again: * gap is either the low watermark or 1% * of the zone, whichever is smaller. */ + testorder = order; balance_gap = min(low_wmark_pages(zone), (zone->present_pages + KSWAPD_ZONE_BALANCE_GAP_RATIO-1) / KSWAPD_ZONE_BALANCE_GAP_RATIO); - if (!zone_watermark_ok_safe(zone, order, + /* + * Kswapd reclaims only single pages when + * COMPACTION_BUILD. Trying too hard to get + * contiguous free pages can result in excessive + * amounts of free memory, and useful things + * getting kicked out of memory. + * Limit the amount of reclaim to something sane, + * plus space for compaction to do its thing. + */ + if (COMPACTION_BUILD) { + testorder = 0; + balance_gap += 2<present_pages; } } .