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 A6163C4321D for ; Fri, 24 Aug 2018 07:52:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6878721581 for ; Fri, 24 Aug 2018 07:52:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6878721581 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 S1727767AbeHXLZ3 (ORCPT ); Fri, 24 Aug 2018 07:25:29 -0400 Received: from mx2.suse.de ([195.135.220.15]:53820 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726969AbeHXLZ3 (ORCPT ); Fri, 24 Aug 2018 07:25:29 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D2C89AF6F; Fri, 24 Aug 2018 07:52:01 +0000 (UTC) Date: Fri, 24 Aug 2018 09:52:01 +0200 From: Michal Hocko To: Roman Gushchin Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Johannes Weiner , Andy Lutomirski , Konstantin Khlebnikov , Tejun Heo , Shakeel Butt Subject: Re: [PATCH v2 1/3] mm: rework memcg kernel stack accounting Message-ID: <20180824075201.GZ29735@dhcp22.suse.cz> References: <20180821213559.14694-1-guro@fb.com> <20180822141213.GO29735@dhcp22.suse.cz> <20180823162347.GA22650@tower.DHCP.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180823162347.GA22650@tower.DHCP.thefacebook.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 On Thu 23-08-18 09:23:50, Roman Gushchin wrote: > On Wed, Aug 22, 2018 at 04:12:13PM +0200, Michal Hocko wrote: [...] > > > @@ -248,9 +253,20 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) > > > static inline void free_thread_stack(struct task_struct *tsk) > > > { > > > #ifdef CONFIG_VMAP_STACK > > > - if (task_stack_vm_area(tsk)) { > > > + struct vm_struct *vm = task_stack_vm_area(tsk); > > > + > > > + if (vm) { > > > int i; > > > > > > + for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) { > > > + mod_memcg_page_state(vm->pages[i], > > > + MEMCG_KERNEL_STACK_KB, > > > + -(int)(PAGE_SIZE / 1024)); > > > + > > > + memcg_kmem_uncharge(vm->pages[i], > > > + compound_order(vm->pages[i])); > > > > when do we have order > 0 here? > > I guess, it's not possible, but hard-coded 1 looked a bit crappy. > Do you think it's better? I guess you meant 0 here. Well, I do not mind, I was just wondering whether I am missing something. -- Michal Hocko SUSE Labs