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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 CE15BC07E95 for ; Tue, 13 Jul 2021 09:32:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B98DF60720 for ; Tue, 13 Jul 2021 09:32:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235071AbhGMJfV (ORCPT ); Tue, 13 Jul 2021 05:35:21 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:45396 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234819AbhGMJfU (ORCPT ); Tue, 13 Jul 2021 05:35:20 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id EA65722119; Tue, 13 Jul 2021 09:32:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1626168749; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=w3Sj149XMB0QShxaoOCWjevBXrahbi07+L3gB+CfwcY=; b=ot/bciPDVvOfiixjXDQj8Exwa60bHVBMfYFRPkmjCAiEVydB3+a/oY7lMDr50NPShpqoaD 5AjG672jzBPfbZWlzKmIsN35BbuWbMUZ9OCy7IcmuYM49Hb9/ejf+jjq7HYlc1WIdgoWzs 9lHYaH0S1NVQF0ZFYxbk6AsTLMXUDsY= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id BB9CAA3B9A; Tue, 13 Jul 2021 09:32:29 +0000 (UTC) Date: Tue, 13 Jul 2021 11:32:29 +0200 From: Michal Hocko To: Miaohe Lin Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, vbabka@suse.cz, axboe@kernel.dk, iamjoonsoo.kim@lge.com, alexs@kernel.org, apopple@nvidia.com, willy@infradead.org, minchan@kernel.org, david@redhat.com, shli@fb.com, hillf.zj@alibaba-inc.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/5] mm/vmscan: fix misleading comment in isolate_lru_pages() Message-ID: References: <20210710100329.49174-1-linmiaohe@huawei.com> <20210710100329.49174-6-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 12-07-21 19:16:47, Miaohe Lin wrote: > On 2021/7/12 15:28, Michal Hocko wrote: > > On Sat 10-07-21 18:03:29, Miaohe Lin wrote: > >> We couldn't know whether the page is being freed elsewhere until we failed > >> to increase the page count. > > > > This is moving a hard to understand comment from one place to another. > > If get_page_unless_zero failed, the page could have been freed elsewhere. I think > this looks straightforward but doesn't help a lot. Are you preferring to just > remove this comment ? Yes the comment in its current form is not really helpful much. Does it deserve a single liner to drop it? Likely not on its own without more changes in that area. -- Michal Hocko SUSE Labs