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 C1294C433DB for ; Mon, 15 Feb 2021 10:26:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75C2064E04 for ; Mon, 15 Feb 2021 10:26:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230171AbhBOK0a (ORCPT ); Mon, 15 Feb 2021 05:26:30 -0500 Received: from mx2.suse.de ([195.135.220.15]:35018 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230073AbhBOKZS (ORCPT ); Mon, 15 Feb 2021 05:25:18 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1613384672; 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=S/uXPqP/TPAc7XRGUiDHNcqY2NlR0ZY7sWeSVPIWRdU=; b=byxFEEer+FNeRJefGNaijsTv6q5BgfdLMmDFs1e5b857DcUUx1kH37qGAJaiZMlddjghyP v/1T9hEEquxK4/1h+tm8tkcdDWZSzsP2N4T6I6up164j8+LGl2u6O9G5c5eob7Wgm8P00B kRekUTvPEJESkt1i5RxABRMr6shqbVE= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 394E5AC32; Mon, 15 Feb 2021 10:24:32 +0000 (UTC) Date: Mon, 15 Feb 2021 11:24:31 +0100 From: Michal Hocko To: Muchun Song Cc: Johannes Weiner , Vladimir Davydov , Andrew Morton , Cgroups , Linux Memory Management List , LKML Subject: Re: [External] Re: [PATCH 4/4] mm: memcontrol: fix swap uncharge on cgroup v2 Message-ID: References: <20210212170159.32153-1-songmuchun@bytedance.com> <20210212170159.32153-4-songmuchun@bytedance.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 15-02-21 18:15:36, Muchun Song wrote: > On Mon, Feb 15, 2021 at 5:47 PM Michal Hocko wrote: > > > > On Sat 13-02-21 01:01:59, Muchun Song wrote: > > > The swap charges the actual number of swap entries on cgroup v2. > > > If a swap cache page is charged successful, and then we uncharge > > > the swap counter. It is wrong on cgroup v2. Because the swap > > > entry is not freed. > > > > Is there any actual problem though? Can you describe the specific > > scenario please? Swap cache charge life time is a bit tricky and I have > > to confess I have to relearn it every time I need to understand it. The > > patch would be much more easier to review if the changelog was much more > > specific. > > I copied the reply to Shakeel here. :-) Not helpful much. I have seen that reply before answering your patch. I really have to say I find it rather annoying to constantly get unclear and cryptic responses from you. This is a subtle area! Make your claims clear and specific so they can be verified. -- Michal Hocko SUSE Labs