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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5216BC433E0 for ; Tue, 7 Jul 2020 10:52:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1C401206DF for ; Tue, 7 Jul 2020 10:52:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C401206DF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 99BFB6B005A; Tue, 7 Jul 2020 06:52:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 94E786B005C; Tue, 7 Jul 2020 06:52:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 83BC16B0062; Tue, 7 Jul 2020 06:52:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0186.hostedemail.com [216.40.44.186]) by kanga.kvack.org (Postfix) with ESMTP id 6DCA16B005A for ; Tue, 7 Jul 2020 06:52:22 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 02F4E1EE6 for ; Tue, 7 Jul 2020 10:52:22 +0000 (UTC) X-FDA: 77010965724.15.scale93_340c63726eb3 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id BE0E91814B0C8 for ; Tue, 7 Jul 2020 10:52:21 +0000 (UTC) X-HE-Tag: scale93_340c63726eb3 X-Filterd-Recvd-Size: 2714 Received: from out4436.biz.mail.alibaba.com (out4436.biz.mail.alibaba.com [47.88.44.36]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Jul 2020 10:52:20 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R451e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04397;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=16;SR=0;TI=SMTPD_---0U20Cnyd_1594119126; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U20Cnyd_1594119126) by smtp.aliyun-inc.com(127.0.0.1); Tue, 07 Jul 2020 18:52:06 +0800 Subject: Re: [PATCH v14 07/20] mm/thp: narrow lru locking To: Matthew Wilcox Cc: akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, yang.shi@linux.alibaba.com, hannes@cmpxchg.org, lkp@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, shakeelb@google.com, iamjoonsoo.kim@lge.com, richard.weiyang@gmail.com References: <1593752873-4493-1-git-send-email-alex.shi@linux.alibaba.com> <1593752873-4493-8-git-send-email-alex.shi@linux.alibaba.com> <124eeef1-ff2b-609e-3bf6-a118100c3f2a@linux.alibaba.com> <20200706113513.GY25523@casper.infradead.org> From: Alex Shi Message-ID: Date: Tue, 7 Jul 2020 18:51:36 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200706113513.GY25523@casper.infradead.org> Content-Type: text/plain; charset=utf-8 X-Rspamd-Queue-Id: BE0E91814B0C8 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000005, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: =E5=9C=A8 2020/7/6 =E4=B8=8B=E5=8D=887:35, Matthew Wilcox =E5=86=99=E9=81= =93: >> Would you like to give some comments or share your concern of this pat= chset, >> specialy for THP part?=20 > I don't have the brain space to understand this patch set fully at > the moment. I'll note that the realtime folks are doing their best to > stamp out users of local_irq_disable(), so they won't be pleased to see > you adding a new one. Also, you removed the comment explaining why the > lock needed to be taken. >=20 Hi Matthew, Thanks for response! As to the local_irq_disable(), we could use local_irq_save(), but Hugh Di= ckin suggest it's not necessary here. Also there are still much local_irq_disa= ble() in code. Hope it would be a big trouble for only one extra. yes, The lru_lock comments is a bit early to remove, that should do in ne= xt=20 TestClearPageLRU part. but since it would be changed soon. It won't be a = critical thing. Anyway I can change it to back in next version. Thanks Alex