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 A7ACCC636CC for ; Tue, 7 Feb 2023 16:52:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231831AbjBGQwr (ORCPT ); Tue, 7 Feb 2023 11:52:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230503AbjBGQwq (ORCPT ); Tue, 7 Feb 2023 11:52:46 -0500 Received: from mail-qt1-x832.google.com (mail-qt1-x832.google.com [IPv6:2607:f8b0:4864:20::832]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D6E946B0 for ; Tue, 7 Feb 2023 08:52:44 -0800 (PST) Received: by mail-qt1-x832.google.com with SMTP id w3so17427749qts.7 for ; Tue, 07 Feb 2023 08:52:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=90LXWSidw5JtQbA5QjDdZbPVfE/311Yqzr/kJ+sttOM=; b=pYf4Wm2yX5Db/EesL6WWX79wefRSPeDXmP+JdbgruotStM4aTAg2EEmqAmFcafVsOQ qVZWuUrBQcBVM89VJJ7Lg4bX/OLfvPC1JnVU38e0oEClpG1YyWHd0+1D5TuFyOmu9tci 7MwIi4JbzEUI59mW7MaUZ/BNcb7O8lzbaqyOkMte4VWLeUgGN2267ypBgPNhYD5pWixE 7FMX6ON/ZNDrK1hq08B5q/9FdOFoJ38kat9YP6xjerL7XjmkjB4pkTIVGToAAidXO5G/ MQeEU/d9tJ/c2Ix5Z2oWzN6/Eq3r3KwCryG0x4+v8QGkNaxF/8oRrWFBcMl3Dd67WCf4 AwwA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=90LXWSidw5JtQbA5QjDdZbPVfE/311Yqzr/kJ+sttOM=; b=YQXJCFHETspekf2i1QFOXOqOAA4xuYIk2Wb3xK6XCLkV3YetFa9ehdjsWxHj8wcai0 8aeD0WJ11+vKq4EIH35DbqrLHr8+qUnsUSs8pMXC+zyQrhrTcMhp9c0qjnd7eqi/PlOs HirUhaEuDiXchYB/WIDrII0oSr7q5YXbkM7mfE7mR6uzVtBKPocAAq9X1D5byjkoR5U/ tqHv/MP0aHGq1VvTQHXylGLfaURM7KkcA3BV5CRYDROLbWbTZ04pKF+Tg9JMNAQLOZXO K1WzKogINc2yzTNJwvrVGI97JFtXrSm+fm5aaiRsns4G8mhHzDxyNGOMwogjjUwJKXWB Lt7w== X-Gm-Message-State: AO0yUKWcO0dJQQuPH2dZ1b4BQUuKW0y5jcPJWxwBJrHGaf1hwvmz6c0m yU+8ytnq18rUdbcTCkeQhvBr9w== X-Google-Smtp-Source: AK7set/uMLJlKX7oaJVhg/E1eUJJiYug4Xd2CDFycpOG8k49bTxnQu/j0dxXX9P9xRATm5qsym0V1A== X-Received: by 2002:a05:622a:54c:b0:3b8:68fa:afc6 with SMTP id m12-20020a05622a054c00b003b868faafc6mr7290880qtx.29.1675788763797; Tue, 07 Feb 2023 08:52:43 -0800 (PST) Received: from localhost (2603-7000-0c01-2716-8f57-5681-ccd3-4a2e.res6.spectrum.com. [2603:7000:c01:2716:8f57:5681:ccd3:4a2e]) by smtp.gmail.com with ESMTPSA id f10-20020ac840ca000000b003b84b92052asm9621428qtm.57.2023.02.07.08.52.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Feb 2023 08:52:43 -0800 (PST) Date: Tue, 7 Feb 2023 11:52:42 -0500 From: Johannes Weiner To: Roman Gushchin Cc: Yang Shi , Michal Hocko , Shakeel Butt , Tejun Heo , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Brauner Subject: Re: [RFC PATCH] mm: memcontrol: don't account swap failures not due to cgroup limits Message-ID: References: <20230202155626.1829121-1-hannes@cmpxchg.org> 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 Fri, Feb 03, 2023 at 11:19:32AM -0800, Roman Gushchin wrote: > On Fri, Feb 03, 2023 at 11:07:30AM -0800, Yang Shi wrote: > > On Fri, Feb 3, 2023 at 11:00 AM Roman Gushchin wrote: > > > > > > On Thu, Feb 02, 2023 at 10:56:26AM -0500, Johannes Weiner wrote: > > > > Christian reports the following situation in a cgroup that doesn't > > > > have memory.swap.max configured: > > > > > > > > $ cat memory.swap.events > > > > high 0 > > > > max 0 > > > > fail 6218 > > > > > > > > Upon closer examination, this is an ARM64 machine that doesn't support > > > > swapping out THPs. > > > > > > Do we expect it to be added any time soon or it's caused by some system > > > limitations? > > > > AFAIK, it has been supported since 6.0. See commit d0637c505f8a1 > > Great, thank you for the link! > Then it looks like we have even fewer reasons to change the interface. Yes, ARM supports it now. But the point wasn't necessarily to fix this because of ARM. THP swap can fall back due to plenty of other reasons, for example fragmentation. It always falls back on swapfiles since they don't have the cluster allocator that bdevs have. The broader point was that we show failures in the cgroup event counter that have nothing to do with the cgroup's configuration.