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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 46089C11D1B for ; Thu, 20 Feb 2020 18:45:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 239892467B for ; Thu, 20 Feb 2020 18:45:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582224349; bh=u4N56QT8EjPNC1GEXgPFUPiBBGSdrjW87sRLlg6bxJ8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=xPK3Z4rHDkMkO8Ea8VLLLPU2KH9L7VxIK/BbBfPTx0y9B40QSxhHXiD1fIUQt9aKl qHUmlmPd9kHcD+5ddtnEEfNWQ6NnIltyxDOuYU8+HOE/pdRLFka4WNXSig6BSfrHmS vbuUccnmrBmpS8EmRGS8tEMYHtHLqflNJGEMDVqc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728820AbgBTSps (ORCPT ); Thu, 20 Feb 2020 13:45:48 -0500 Received: from mail-qt1-f193.google.com ([209.85.160.193]:41259 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728111AbgBTSpr (ORCPT ); Thu, 20 Feb 2020 13:45:47 -0500 Received: by mail-qt1-f193.google.com with SMTP id l21so3617558qtr.8; Thu, 20 Feb 2020 10:45:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ajjnncCD8dG0G18fVGbEVN7FP1csi2qzGtdLhYXXJTU=; b=k/vpOSde9bMUoOkP1G2/1I25Nn9Pkv0cytj97/bjAuSIclk+m4KQ9S0ziULuviFMs9 c6vb59sXLtBdSul8JNMDN9b22s/HaXZqEDqZVUUgXxNzpc7+RQuul8Lh87CBQrY8TG3b yeVKaW3Bcp9oIDJS2uYK6b0btASzCNPTQaNt4mwNERLhrW2G+KqIsbMBhMm9SXREycvV j/K7EMs16439ppT5r1FvGQRPftTQKxEEa69Oq9TofNUu2SJGZM7OqXVNPpPTYwvgce4v wW8oxpMW8jTdFf8kowzQY6+ON6pmqStIvwfyWeN0NhVNmwZhaMHrCqR6Xy/TfGZu19ch YULQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=ajjnncCD8dG0G18fVGbEVN7FP1csi2qzGtdLhYXXJTU=; b=MiRq1M5z2j8Q9wqPG6frhWM+vPmm7WO6XyCCCs/Tkm+ipxqpG7nxmbtmnTxbw6orvV L5/Ljy5/uDNrRftJNHdUqtsyFRd4cSGn8eZPrX4hgtYWBwRg1uXLmumZkoSVhauxnVqW QzBoHYp5aad9hI4Ong2BMmZEq9mVkEesJEtCjQ0yTN0Dzc/M2LMyRXLYqWVeYgsDkNbh UMmuFXr+pd4jg/ReTrOaj/yw1mXdZjxqfHMb+3wzCu4njHXRPMdZwuQvpjOj8ymSCtmw Q8HVtmWsg234cz5o3AUV+AqHQ6q3wJ0QSwoctPZO9F02qUr70pD6BJPRCZp1fnid3J8D sc5g== X-Gm-Message-State: APjAAAVEAyNUc9I0VTRjqQ/EL+4ly9eTOpgY56rZoYBULxIXD+HBp07s YNassZs/2UiOtopRp1L2YsQ= X-Google-Smtp-Source: APXvYqwr8QZEGjR+02xUZfnyfEhH/c3g1ZpRFCpisQx2XA9vthKAPCCYNwk1zQ/xPc6ejfIm8rgcFQ== X-Received: by 2002:ac8:6054:: with SMTP id k20mr27102688qtm.92.1582224346333; Thu, 20 Feb 2020 10:45:46 -0800 (PST) Received: from localhost ([2620:10d:c091:500::55b1]) by smtp.gmail.com with ESMTPSA id z1sm194156qtq.69.2020.02.20.10.45.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Feb 2020 10:45:45 -0800 (PST) Date: Thu, 20 Feb 2020 13:45:45 -0500 From: Tejun Heo To: Daniel Jordan Cc: Johannes Weiner , Michal Hocko , Andrew Morton , Roman Gushchin , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Peter Zijlstra Subject: Re: [PATCH] mm: memcontrol: asynchronous reclaim for memory.high Message-ID: <20200220184545.GH698990@mtj.thefacebook.com> References: <20200219181219.54356-1-hannes@cmpxchg.org> <20200219183731.GC11847@dhcp22.suse.cz> <20200219191618.GB54486@cmpxchg.org> <20200219195332.GE11847@dhcp22.suse.cz> <20200219214112.4kt573kyzbvmbvn3@ca-dmjordan1.us.oracle.com> <20200219220859.GF54486@cmpxchg.org> <20200220154524.dql3i5brnjjwecft@ca-dmjordan1.us.oracle.com> <20200220155651.GG698990@mtj.thefacebook.com> <20200220182326.ubcjycaubgykiy6e@ca-dmjordan1.us.oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200220182326.ubcjycaubgykiy6e@ca-dmjordan1.us.oracle.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Thu, Feb 20, 2020 at 01:23:26PM -0500, Daniel Jordan wrote: > The amount of work wouldn't seem to matter as long as the kernel thread stays > in the cgroup and lives long enough. There's only the one-time cost of > attaching it when it's forked. That seems doable for unbound workqueues (the > async reclaim), but may not be for the network packets. The setup cost can be lazy optimized but it'd still have to bounce the tiny pieces of work to different threads instead of processing them in one fell swoop from the same context, which most likely is gonna be untenably expensive. Thanks. -- tejun