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=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT 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 B9DA0C004D3 for ; Mon, 22 Oct 2018 12:51:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E5F520890 for ; Mon, 22 Oct 2018 12:51:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E5F520890 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1728374AbeJVVKO (ORCPT ); Mon, 22 Oct 2018 17:10:14 -0400 Received: from mx2.suse.de ([195.135.220.15]:40892 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727210AbeJVVKO (ORCPT ); Mon, 22 Oct 2018 17:10:14 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id B813AAFC0; Mon, 22 Oct 2018 12:51:45 +0000 (UTC) Date: Mon, 22 Oct 2018 14:51:42 +0200 From: Michal Hocko To: "Uladzislau Rezki (Sony)" Cc: 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: <20181022125142.GD18839@dhcp22.suse.cz> References: <20181019173538.590-1-urezki@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181019173538.590-1-urezki@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? > 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. 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. > > 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. Thanks a lot! -- Michal Hocko SUSE Labs