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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_NEOMUTT 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 026FBC67863 for ; Mon, 22 Oct 2018 16:53:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7985E20663 for ; Mon, 22 Oct 2018 16:53:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JAAETX+F" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7985E20663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com 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 S1728533AbeJWBMP (ORCPT ); Mon, 22 Oct 2018 21:12:15 -0400 Received: from mail-lj1-f194.google.com ([209.85.208.194]:44287 "EHLO mail-lj1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727820AbeJWBMP (ORCPT ); Mon, 22 Oct 2018 21:12:15 -0400 Received: by mail-lj1-f194.google.com with SMTP id v6-v6so37613544ljc.11 for ; Mon, 22 Oct 2018 09:52:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=OQRy6bWiFyWNxW02VDulhGCt9vf+K4KgUWsQA2ATsgE=; b=JAAETX+FvYV+UxfgdrS3de/cpZaW0BSWdZyQIts+64RzecX3M7dSix+h72xBVrWKKM VcfUlqi8j4qTdsQKj2sq42umLMDjXPDDQRMm587Qz8/qjooTdP7fcbGj7cu2i5zKa/mN kZPJFgDDcmiNKWdFQSipirTZscOZBwybK/lXqSeLwv9WMC+hd32HGUmtjky2umK27eXe qEdtu3uMekI+A1sx1mpR6qIH2WL0xlbFMc5Pgq53zXpqt77yxokugTIdWL7KrZ5D5w73 wm2ivUz4/AV3yeBx6lHMXZdY4S45w7SLFk65ViUScyCk+nld+lA0Btnt5QFT3DHkXBCt KKmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=OQRy6bWiFyWNxW02VDulhGCt9vf+K4KgUWsQA2ATsgE=; b=Wv54HYjLLm0oOJhcFtjOvBynmotrCqVZv4OcGF54dFU2KRwYCh4+3JuYjjyzaFIsxc dxUHg2rNcniSI9Eee5B8aIl9s0zLqn3O7uZE8UBPqBXX3LJpIa7HvkgjlIRJfl0OhVS2 QGv02USN6A71aCnbuzjvVIpmSVTW9WsWMnALwieHaoBYYibKwJlcSO/nQw3yhpJCOHxY KSehbHFeNDeP/t7iOWYx660JaK9cUc8tizGi2FIEijJrmp1ozmvPv46R58+pWb4nvix0 3RgCXzt37vNlainImBgcuqQj8oPG8gKHpqgO4U+JiNVp6xYHvb1Cny9Cudj1ib9FGJeJ 28jA== X-Gm-Message-State: ABuFfoh8d43ZG9h5MinXun7rNM2SoDwzv/I/NSec77fRMrI1E6gsdItY EpEhF1J8aKwz/VZZVrJsid4= X-Google-Smtp-Source: ACcGV61v8kfBpSXSodu1eJb1fjdQATMuU2DNJ7quNnVCIkeHwbFOQ+nAW92cDzMyNw1kiQn6piIn7A== X-Received: by 2002:a2e:121:: with SMTP id 33-v6mr29611477ljb.96.1540227177197; Mon, 22 Oct 2018 09:52:57 -0700 (PDT) Received: from pc636 ([37.139.158.167]) by smtp.gmail.com with ESMTPSA id 1-v6sm6968219ljc.46.2018.10.22.09.52.55 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 22 Oct 2018 09:52:56 -0700 (PDT) From: Uladzislau Rezki X-Google-Original-From: Uladzislau Rezki Date: Mon, 22 Oct 2018 18:52:53 +0200 To: Michal Hocko Cc: "Uladzislau Rezki (Sony)" , Matthew Wilcox , Andrew Morton , linux-mm@kvack.org, LKML , Thomas Garnier , Oleksiy Avramchenko , Steven Rostedt , Joel Fernandes , Thomas Gleixner , Ingo Molnar , Tejun Heo Subject: Re: [RFC PATCH 0/2] improve vmalloc allocation Message-ID: <20181022165253.uphv3xzqivh44o3d@pc636> References: <20181019173538.590-1-urezki@gmail.com> <20181022125142.GD18839@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181022125142.GD18839@dhcp22.suse.cz> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 22, 2018 at 02:51:42PM +0200, Michal Hocko wrote: > Hi, > I haven't read through the implementation yet but I have say that I > really love this cover letter. It is clear on intetion, it covers design > from high level enough to start discussion and provides a very nice > testing coverage. Nice work! > > I also think that we need a better performing vmalloc implementation > long term because of the increasing number of kvmalloc users. > > I just have two mostly workflow specific comments. > > > A test-suite patch you can find here, it is based on 4.18 kernel. > > ftp://vps418301.ovh.net/incoming/0001-mm-vmalloc-stress-test-suite-v4.18.patch > > Can you fit this stress test into the standard self test machinery? > If you mean "tools/testing/selftests", then i can fit that as a kernel module. But not all the tests i can trigger from kernel module, because 3 of 8 tests use __vmalloc_node_range() function that is not marked as EXPORT_SYMBOL. > > It is fixed by second commit in this series. Please see more description in > > the commit message of the patch. > > Bug fixes should go first and new functionality should be built on top. > Thanks for the good point. > A kernel crash sounds serious enough to have a fix marked for stable. If > the fix is too hard/complex then we might consider a revert of the > faulty commit. > The fix is straightforward and easy. It adds a threshold passing which we forbid cond_resched_lock() and continue draining of lazy pages. > > > > 3) This one is related to PCPU allocator(see pcpu_alloc_test()). In that > > stress test case i see that SUnreclaim(/proc/meminfo) parameter gets increased, > > i.e. there is a memory leek somewhere in percpu allocator. It sounds like > > a memory that is allocated by pcpu_get_vm_areas() sometimes is not freed. > > Resulting in memory leaking or "Kernel panic": > > > > ---[ end Kernel panic - not syncing: Out of memory and no killable processes... > > It would be great to pin point this one down before the rework as well. > Actually it has been fixed recently. Roman Gushchin pointed to the: 6685b357363b ("percpu: stop leaking bitmap metadata blocks") i have checked, it works fine and fixes a leak i see. Thank you! -- Vlad Rezki > Thanks a lot! > -- > Michal Hocko > SUSE Labs