From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F64DC6FD18 for ; Wed, 19 Apr 2023 07:35:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232323AbjDSHfC (ORCPT ); Wed, 19 Apr 2023 03:35:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231612AbjDSHe5 (ORCPT ); Wed, 19 Apr 2023 03:34:57 -0400 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73AA97EFD for ; Wed, 19 Apr 2023 00:34:56 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046060;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VgU2AEu_1681889692; Received: from 30.97.48.60(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VgU2AEu_1681889692) by smtp.aliyun-inc.com; Wed, 19 Apr 2023 15:34:53 +0800 Message-ID: Date: Wed, 19 Apr 2023 15:34:54 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH] migrate_pages_batch: fix statistics for longterm pin retry To: Huang Ying , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alistair Popple , David Hildenbrand , Yang Shi , Zi Yan References: <20230416235929.1040194-1-ying.huang@intel.com> From: Baolin Wang In-Reply-To: <20230416235929.1040194-1-ying.huang@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/17/2023 7:59 AM, Huang Ying wrote: > In commit fd4a7ac32918 ("mm: migrate: try again if THP split is failed > due to page refcnt"), if the THP splitting fails due to page reference > count, we will retry to improve migration successful rate. But the > failed splitting is counted as migration failure and migration retry, > which will cause duplicated failure counting. So, in this patch, this > is fixed via undoing the failure counting if we decide to retry. The > patch is tested via failure injection. Makes sense to me. Thanks. Reviewed-by: Baolin Wang > Fixes: fd4a7ac32918 ("mm: migrate: try again if THP split is failed due to page refcnt") > Signed-off-by: "Huang, Ying" > Cc: Baolin Wang > Cc: Alistair Popple > Cc: David Hildenbrand > Cc: Yang Shi > Cc: Zi Yan > --- > mm/migrate.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/migrate.c b/mm/migrate.c > index b34a0f383795..47a1e8445f45 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1743,6 +1743,9 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page, > large_retry++; > thp_retry += is_thp; > nr_retry_pages += nr_pages; > + /* Undo duplicated failure counting. */ > + nr_large_failed--; > + stats->nr_thp_failed -= is_thp; > break; > } > }