Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932538Ab0KCPfr (ORCPT ); Wed, 3 Nov 2010 11:35:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932415Ab0KCPbG (ORCPT ); Wed, 3 Nov 2010 11:31:06 -0400 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [PATCH 51 of 66] set recommended min free kbytes X-Mercurial-Node: e4c3f336872db7bfbf58f7fa000053906b78e80f Message-Id: In-Reply-To: References: User-Agent: Mercurial-patchbomb/1.4.1 Date: Wed, 03 Nov 2010 16:28:26 +0100 From: Andrea Arcangeli To: linux-mm@kvack.org, Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org Cc: Marcelo Tosatti , Adam Litke , Avi Kivity , Hugh Dickins , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, KOSAKI Motohiro , Balbir Singh , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Daisuke Nishimura , Chris Mason , Borislav Petkov Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2738 Lines: 96 From: Andrea Arcangeli If transparent hugepage is enabled initialize min_free_kbytes to an optimal value by default. This moves the hugeadm algorithm in kernel. Signed-off-by: Andrea Arcangeli --- diff --git a/mm/huge_memory.c b/mm/huge_memory.c --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -85,6 +85,47 @@ struct khugepaged_scan { .mm_head = LIST_HEAD_INIT(khugepaged_scan.mm_head), }; + +static int set_recommended_min_free_kbytes(void) +{ + struct zone *zone; + int nr_zones = 0; + unsigned long recommended_min; + extern int min_free_kbytes; + + if (!test_bit(TRANSPARENT_HUGEPAGE_FLAG, + &transparent_hugepage_flags) && + !test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, + &transparent_hugepage_flags)) + return 0; + + for_each_populated_zone(zone) + nr_zones++; + + /* Make sure at least 2 hugepages are free for MIGRATE_RESERVE */ + recommended_min = HPAGE_PMD_NR * nr_zones * 2; + + /* + * Make sure that on average at least two pageblocks are almost free + * of another type, one for a migratetype to fall back to and a + * second to avoid subsequent fallbacks of other types There are 3 + * MIGRATE_TYPES we care about. + */ + recommended_min += HPAGE_PMD_NR * nr_zones * 3 * 3; + + /* don't ever allow to reserve more than 5% of the lowmem */ + recommended_min = min(recommended_min, + (unsigned long) nr_free_buffer_pages() / 20); + recommended_min <<= (PAGE_SHIFT-10); + + if (recommended_min > min_free_kbytes) { + min_free_kbytes = recommended_min; + setup_per_zone_wmarks(); + } + return 0; +} +late_initcall(set_recommended_min_free_kbytes); + static int start_khugepaged(void) { int err = 0; @@ -108,6 +149,8 @@ static int start_khugepaged(void) mutex_unlock(&khugepaged_mutex); if (wakeup) wake_up_interruptible(&khugepaged_wait); + + set_recommended_min_free_kbytes(); } else /* wakeup to exit */ wake_up_interruptible(&khugepaged_wait); @@ -177,6 +220,13 @@ static ssize_t enabled_store(struct kobj ret = err; } + if (ret > 0 && + (test_bit(TRANSPARENT_HUGEPAGE_FLAG, + &transparent_hugepage_flags) || + test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, + &transparent_hugepage_flags))) + set_recommended_min_free_kbytes(); + return ret; } static struct kobj_attribute enabled_attr = @@ -464,6 +514,8 @@ static int __init hugepage_init(void) start_khugepaged(); + set_recommended_min_free_kbytes(); + out: return err; } -- 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/