From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx133.postini.com [74.125.245.133]) by kanga.kvack.org (Postfix) with SMTP id 7B9726B0033 for ; Sun, 25 Aug 2013 19:24:03 -0400 (EDT) Received: from /spool/local by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 26 Aug 2013 09:13:28 +1000 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [9.190.235.21]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 208B93578051 for ; Mon, 26 Aug 2013 09:23:54 +1000 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r7PNNXHD66912390 for ; Mon, 26 Aug 2013 09:23:43 +1000 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r7PNNh3x026874 for ; Mon, 26 Aug 2013 09:23:44 +1000 Date: Mon, 26 Aug 2013 07:23:42 +0800 From: Wanpeng Li Subject: Re: [PATCH v2 5/7] mm/hwpoison: don't set migration type twice to avoid hold heavy contend zone->lock Message-ID: <20130825232341.GA22730@hacker.(null)> Reply-To: Wanpeng Li References: <1377253841-17620-1-git-send-email-liwanp@linux.vnet.ibm.com> <1377253841-17620-5-git-send-email-liwanp@linux.vnet.ibm.com> <1377268598-md0gqi8g-mutt-n-horiguchi@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1377268598-md0gqi8g-mutt-n-horiguchi@ah.jp.nec.com> Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Andrew Morton , Andi Kleen , Fengguang Wu , Tony Luck , gong.chen@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Fri, Aug 23, 2013 at 10:36:38AM -0400, Naoya Horiguchi wrote: >On Fri, Aug 23, 2013 at 06:30:39PM +0800, Wanpeng Li wrote: >> v1 -> v2: >> * add more explanation in patch description. >> >> Set pageblock migration type will hold zone->lock which is heavy contended >> in system to avoid race. However, soft offline page will set pageblock >> migration type twice during get page if the page is in used, not hugetlbfs >> page and not on lru list. There is unnecessary to set the pageblock migration >> type and hold heavy contended zone->lock again if the first round get page >> have already set the pageblock to right migration type. >> >> The trick here is migration type is MIGRATE_ISOLATE. There are other two parts >> can change MIGRATE_ISOLATE except hwpoison. One is memory hoplug, however, we >> hold lock_memory_hotplug() which avoid race. The second is CMA which umovable >> page allocation requst can't fallback to. So it's safe here. >> >> Signed-off-by: Wanpeng Li >> --- >> mm/memory-failure.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >> index 297965e..f357c91 100644 >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -1426,7 +1426,8 @@ static int __get_any_page(struct page *p, unsigned long pfn, int flags) >> * was free. This flag should be kept set until the source page >> * is freed and PG_hwpoison on it is set. >> */ >> - set_migratetype_isolate(p, true); >> + if (get_pageblock_migratetype(p) == MIGRATE_ISOLATE) >> + set_migratetype_isolate(p, true); > >Do you really mean "we set MIGRATE_ISOLATE only if it's already set?" > Ouch, it's my fault, I will fix it in next version. ;-) Regards, Wanpeng Li >Thanks, >Naoya Horiguchi > >> /* >> * When the target page is a free hugepage, just remove it >> * from free hugepage list. >> -- >> 1.8.1.2 >> >> -- >> To unsubscribe, send a message with 'unsubscribe linux-mm' in >> the body to majordomo@kvack.org. For more info on Linux MM, >> see: http://www.linux-mm.org/ . >> Don't email: email@kvack.org >> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org