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 78F7CC001DF for ; Wed, 2 Aug 2023 02:59:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231821AbjHBC7M (ORCPT ); Tue, 1 Aug 2023 22:59:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229597AbjHBC7K (ORCPT ); Tue, 1 Aug 2023 22:59:10 -0400 Received: from out30-98.freemail.mail.aliyun.com (out30-98.freemail.mail.aliyun.com [115.124.30.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 481E9EC for ; Tue, 1 Aug 2023 19:59:09 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R131e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VotEpv._1690945144; Received: from 30.97.48.77(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VotEpv._1690945144) by smtp.aliyun-inc.com; Wed, 02 Aug 2023 10:59:05 +0800 Message-ID: Date: Wed, 2 Aug 2023 10:59:32 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH 4/5] mm/compaction: remove unnecessary cursor page in isolate_freepages_block To: Kemeng Shi , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Cc: mgorman@techsingularity.net, willy@infradead.org, david@redhat.com References: <20230729174354.2239980-1-shikemeng@huaweicloud.com> <20230729174354.2239980-5-shikemeng@huaweicloud.com> From: Baolin Wang In-Reply-To: <20230729174354.2239980-5-shikemeng@huaweicloud.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 7/30/2023 1:43 AM, Kemeng Shi wrote: > The cursor is only used for page forward currently. We can simply move page > forward directly to remove unnecessary cursor. > > Signed-off-by: Kemeng Shi LGTM. Reviewed-by: Baolin Wang > --- > mm/compaction.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 65791a74c5e8..cfb661f4ce23 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -589,7 +589,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > bool strict) > { > int nr_scanned = 0, total_isolated = 0; > - struct page *cursor; > + struct page *page; > unsigned long flags = 0; > spinlock_t *locked = NULL; > unsigned long blockpfn = *start_pfn; > @@ -599,12 +599,11 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > if (strict) > stride = 1; > > - cursor = pfn_to_page(blockpfn); > + page = pfn_to_page(blockpfn); > > /* Isolate free pages. */ > - for (; blockpfn < end_pfn; blockpfn += stride, cursor += stride) { > + for (; blockpfn < end_pfn; blockpfn += stride, page += stride) { > int isolated; > - struct page *page = cursor; > > /* > * Periodically drop the lock (if held) regardless of its > @@ -628,7 +627,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > > if (likely(order <= MAX_ORDER)) { > blockpfn += (1UL << order) - 1; > - cursor += (1UL << order) - 1; > + page += (1UL << order) - 1; > nr_scanned += (1UL << order) - 1; > } > goto isolate_fail; > @@ -665,7 +664,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, > } > /* Advance to the end of split page */ > blockpfn += isolated - 1; > - cursor += isolated - 1; > + page += isolated - 1; > continue; > > isolate_fail: