Received: by 2002:a25:ab43:0:0:0:0:0 with SMTP id u61csp651967ybi; Fri, 24 May 2019 09:14:17 -0700 (PDT) X-Google-Smtp-Source: APXvYqx0/wBhXa60FO6W6k1E/Q7yKAvIpb9EnRsOgKPuBw6U3pSLGrQS+6KHXeN13IxlzVMl0T1/ X-Received: by 2002:a17:902:8e8a:: with SMTP id bg10mr52209937plb.247.1558714457060; Fri, 24 May 2019 09:14:17 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1558714457; cv=none; d=google.com; s=arc-20160816; b=Y6YYlJ5M/cGHbUxMRZbK43INijjGA1hveK6ViPIt//r35jGNQ8+lwBxIJe16Lps1M2 U02xQFewKu2lHObqxX+BejDYxBXyoXZiX/PlMsgReTUmxk1jfflPqjWuWvjDmN1McM4V GUke9z9H0FGgHz5Qa3GqV5m9wbg6gKHjUb810Sw2o5Trx6fEYbo9XHnJD1USRz9DNl8+ 03+QqGX8iHNtL+mYbNemS/zTMch24IN8c1mBdF+sAqbQyPeZNEmJY+rAeUTEe5TNtPKz 9Qs88oOJxXCFGGUZuMXSgObmr1oaAPRTDCSdi/j9tREAf/vyOvdeyBXuqxJ0vVLDJAXa Qd6w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=XMpCB89ytjbHczxqQZJ1ZkGk4p/wzfOhXhEuznTtcMU=; b=J6+cWkcSf9ouz1gQUSHpXvhiO+xlLmDdNdyVLNB7775tzz3RM49nH74Uf+FHqz2Osm 6nRf9alhy+9yr4OWp/lfw0f2LsiJ8qk9ARPVJ7UJ2vym+9oBgr+bOzUcTxOqahXjRHWW eys1Ny46g1NNOPAz7VaNiMP9P2l1vUesf972BUgboMP570q7SUMowXpbOie/Wrj3MJtg GX4rMF7Q/sZUV/1YrG1OTE8xMs6jXksYL0tG2PvW4/i1coaOK7boQbGg1Osywv71xFBh /L/237oSU+PwRfP2MODoS/dGY4j7/TAhR5dIcUaPVXjCi4yshKxzt2Iij9Byca39HBdN 0MfA== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=VdgAfLUX; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id a91si354927pld.10.2019.05.24.09.14.01; Fri, 24 May 2019 09:14:17 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=VdgAfLUX; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390789AbfEXQLu (ORCPT + 99 others); Fri, 24 May 2019 12:11:50 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:35060 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390411AbfEXQLu (ORCPT ); Fri, 24 May 2019 12:11:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=XMpCB89ytjbHczxqQZJ1ZkGk4p/wzfOhXhEuznTtcMU=; b=VdgAfLUXLCJlXG5l/7G3EXePj SSJwDOnYPi2jv9q8sjeH/rp5wl1hTE0k/mlDMPdly9vpf0znyQWHE8P/xVkTzmwchhL3NdHUR7Zut n0dGIxrqop8fek0MoEG+PplDVqzElFrd1g2zn+17UZgMLiGSfdYN5pHxWDRasOM76wm59MNcuHm3e W+jzXozQbR427BFuT7WuqXHdnjX8+XTo6y+4gsoqt+cCg+b1HDipQVf4KCcyy1Fnn8fUmaDw9HUBS 80J/IN9BUnKAmEqEy0gKcjABkN60UlsvYuSKfiBxJEEcLE4HITTrK43TTI0zj2SL340n2TrIdrYna rs1KInx3w==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hUCnK-00037T-RC; Fri, 24 May 2019 16:11:46 +0000 Date: Fri, 24 May 2019 09:11:46 -0700 From: Matthew Wilcox To: Johannes Weiner Cc: Shakeel Butt , Andrew Morton , Linux MM , linux-fsdevel , LKML , Kernel Team Subject: Re: xarray breaks thrashing detection and cgroup isolation Message-ID: <20190524161146.GC1075@bombadil.infradead.org> References: <20190523174349.GA10939@cmpxchg.org> <20190523183713.GA14517@bombadil.infradead.org> <20190523190032.GA7873@bombadil.infradead.org> <20190523192117.GA5723@cmpxchg.org> <20190523194130.GA4598@bombadil.infradead.org> <20190523195933.GA6404@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190523195933.GA6404@cmpxchg.org> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 23, 2019 at 03:59:33PM -0400, Johannes Weiner wrote: > My point is that we cannot have random drivers' internal data > structures charge to and pin cgroups indefinitely just because they > happen to do the modprobing or otherwise interact with the driver. > > It makes no sense in terms of performance or cgroup semantics. But according to Roman, you already have that problem with the page cache. https://lore.kernel.org/linux-mm/20190522222254.GA5700@castle/T/ So this argument doesn't make sense to me.