From mboxrd@z Thu Jan 1 00:00:00 1970 From: "KOSAKI Motohiro" Subject: [PATCH 7/8][for -mm] mem_notify v6: ignore very small zone for prevent incorrect low mem notify Date: Sun, 10 Feb 2008 00:26:41 +0900 Message-ID: <2f11576a0802090726pa17d91crc1067554100f715f@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kosaki.motohiro@jp.fujitsu.com, "Marcelo Tosatti" , "Daniel Spang" , "Rik van Riel" , "Andrew Morton" , "Alan Cox" , linux-fsdevel@vger.kernel.org, "Pavel Machek" , "Al Boldi" , "Jon Masters" , "Zan Lynx" To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Return-path: Received: from py-out-1112.google.com ([64.233.166.182]:39725 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752535AbYBIP0m (ORCPT ); Sat, 9 Feb 2008 10:26:42 -0500 Received: by py-out-1112.google.com with SMTP id u52so5947590pyb.10 for ; Sat, 09 Feb 2008 07:26:41 -0800 (PST) Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-ID: on X86, ZONE_DMA is very very small. it cause undesirable low mem notification. It should ignored. but on other some architecture, ZONE_DMA have 4GB. 4GB is large as it is not possible to ignored. therefore, ignore or not is decided by zone size. ChangeLog: v5: new Signed-off-by: KOSAKI Motohiro --- include/linux/mem_notify.h | 3 +++ mm/page_alloc.c | 6 +++++- 2 files changed, 8 insertions(+), 1 deletion(-) Index: b/include/linux/mem_notify.h =================================================================== --- a/include/linux/mem_notify.h 2008-01-23 22:06:04.000000000 +0900 +++ b/include/linux/mem_notify.h 2008-01-23 22:08:02.000000000 +0900 @@ -22,6 +22,9 @@ static inline void memory_pressure_notif unsigned long target; unsigned long pages_high, pages_free, pages_reserve; + if (unlikely(zone->mem_notify_status == -1)) + return; + if (pressure) { target = atomic_long_read(&last_mem_notify) + MEM_NOTIFY_FREQ; if (likely(time_before(jiffies, target))) Index: b/mm/page_alloc.c =================================================================== --- a/mm/page_alloc.c 2008-01-23 22:07:57.000000000 +0900 +++ b/mm/page_alloc.c 2008-01-23 22:08:02.000000000 +0900 @@ -3470,7 +3470,11 @@ static void __meminit free_area_init_cor zone->zone_pgdat = pgdat; zone->prev_priority = DEF_PRIORITY; - zone->mem_notify_status = 0; + + if (zone->present_pages < (pgdat->node_present_pages / 10)) + zone->mem_notify_status = -1; + else + zone->mem_notify_status = 0; zone_pcp_init(zone); INIT_LIST_HEAD(&zone->active_list);