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=-0.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID autolearn=ham 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 15A81C43141 for ; Wed, 20 Jun 2018 19:33:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B6B95208B1 for ; Wed, 20 Jun 2018 19:33:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=cmpxchg.org header.i=@cmpxchg.org header.b="NQ5WRFGa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B6B95208B1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cmpxchg.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754801AbeFTTdb (ORCPT ); Wed, 20 Jun 2018 15:33:31 -0400 Received: from gum.cmpxchg.org ([85.214.110.215]:48630 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754653AbeFTTda (ORCPT ); Wed, 20 Jun 2018 15:33:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=cmpxchg.org ; s=x; 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=5JdjDvMk5yQ1H5dvBF4jlKKN5fQUxG40qqisxcfxRT0=; b=NQ5WRFGaHOb/vqtt++qEUzLD6P bRZx0l/eB2ZAKEAoh5baSeSPJ76CVAT+Rb91vIoKAv/aTTWzxdvJ6VIN+LE8rwG0SLX+jBySYA3+D omiDWlWGkzX3qIul/40fCa7/mWhNHrqCvhyBgXS4UGWyI+oyQ5TS14oQBOAMeDFMznhU=; Date: Wed, 20 Jun 2018 15:35:49 -0400 From: Johannes Weiner To: Michal Hocko Cc: linux-mm@kvack.org, Greg Thelen , Shakeel Butt , Andrew Morton , LKML Subject: Re: [RFC PATCH] memcg, oom: move out_of_memory back to the charge path Message-ID: <20180620193549.GA4734@cmpxchg.org> References: <20180620103736.13880-1-mhocko@kernel.org> <20180620151812.GA2441@cmpxchg.org> <20180620153148.GO13685@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180620153148.GO13685@dhcp22.suse.cz> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 20, 2018 at 05:31:48PM +0200, Michal Hocko wrote: > This? > if (order > PAGE_ALLOC_COSTLY_ORDER) > return OOM_SKIPPED; > > /* > * We are in the middle of the charge context here, so we > * don't want to block when potentially sitting on a callstack > * that holds all kinds of filesystem and mm locks. > * > * cgroup1 allows disabling the OOM killer and waiting for outside > * handling until the charge can succeed; remember the context and put > * the task to sleep at the end of the page fault when all locks are > * released. > * > * On the other hand, in-kernel OOM killer allows for an async victim > * memory reclaim (oom_reaper) and that means that we are not solely > * relying on the oom victim to make a forward progress and we can > * invoke the oom killer here. > * > * Please note that mem_cgroup_oom_synchronize might fail to find a > * victim and then we have rely on mem_cgroup_oom_synchronize otherwise > * we would fall back to the global oom killer in pagefault_out_of_memory > */ > if (memcg->oom_kill_disable) { > if (!current->memcg_may_oom) > return OOM_SKIPPED; > css_get(&memcg->css); > current->memcg_in_oom = memcg; > current->memcg_oom_gfp_mask = mask; > current->memcg_oom_order = order; > > return OOM_ASYNC; > } > > if (mem_cgroup_out_of_memory(memcg, mask, order)) > return OOM_SUCCESS; > > WARN(!current->memcg_may_oom, > "Memory cgroup charge failed because of no reclaimable memory! " > "This looks like a misconfiguration or a kernel bug."); > return OOM_FAILED; Yep, this looks good IMO.