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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AF4DC433EF for ; Fri, 20 May 2022 16:57:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351931AbiETQ47 (ORCPT ); Fri, 20 May 2022 12:56:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237781AbiETQ4x (ORCPT ); Fri, 20 May 2022 12:56:53 -0400 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE9C65C87C for ; Fri, 20 May 2022 09:56:51 -0700 (PDT) Received: by mail-pf1-x434.google.com with SMTP id y41so8211972pfw.12 for ; Fri, 20 May 2022 09:56:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=L9Uqg73Lka5chFS5zb9bS7SoEX4aGwiCW9rsgcbKHU8=; b=WCgjyI/pbMDZt70/ehioRounN5pA+7LkAnLwVBt5i2W43nM7tKoH6B5ttsBfWBgo6D ki/kXFgEIVboqXvyQa7Ju8Fe4j2gUlJDvQJ/z1Izt5yPYUeHzutkgKgMvjwLrulEG1hK hYg+HgyBXqyq/Z/nhlE7+ssXsm4fP2u2Ob1gqHeRYkLyEKVEmij0ed4Mua47CxL8W+6u eN0vFWoaM6bhlCvvxyG1dcvexERXpbuStK1Hp6VfxRKuHrI5RDL7hksQ7bMWM7ynVKmQ VvZS5J/C7XumERU5SOsgWCrqosIk8n2xBtOuih/QHUYxR3qQWVyCWhRQaxjLOplJQbrE dVNA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=L9Uqg73Lka5chFS5zb9bS7SoEX4aGwiCW9rsgcbKHU8=; b=GZXmaC6dllbVUSy3v6clX1YSoyqgqZIq8Lppg96KkSQtBef81pD9LMI3VtPtg7UnDW 2sQ3VmAuzwxIz0RzNVg/gv4MA8sJ3SnlFpoihCq9pQZrpmsMgUBsYnF/J4xFOU1EvOyF eQgTDxWM/2ki8KXqdzRmebYzdeYbuXq/asP+pVNHZ3NwwOmvwx87ZaxVPGxzCCnKPH0F Mc0PrqDMtgVwq5qLic9FTqL7p9zAKtenDHJn29eYAkdLJ2k8+NZ2XQWkFYKYJSThHqb3 vk0XdrBik4jalLk6wF1qrasq6Psd8IwMI9sxQtb+QI53GD2sxPOXRMBn7wu68Ncg1Vl4 fThw== X-Gm-Message-State: AOAM5322kXiexJigx8NmV6MQ0+RootrjCQKp3G0u0Jq/yk714RrBlkzJ AqcqYs3Ta5j8r+Ybe8F55xVIrQ== X-Google-Smtp-Source: ABdhPJxxwklaCHPwxufCg4de+9ueaGPfNoNDXbigS4fAynaoaFEgIm1jY/OTJrmDMijuou7j+TuQWg== X-Received: by 2002:a05:6a00:1709:b0:505:fa47:b611 with SMTP id h9-20020a056a00170900b00505fa47b611mr10982307pfc.65.1653065811417; Fri, 20 May 2022 09:56:51 -0700 (PDT) Received: from [192.168.254.17] ([50.39.160.154]) by smtp.gmail.com with ESMTPSA id iw3-20020a170903044300b00161a2d98a8esm5903314plb.226.2022.05.20.09.56.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 20 May 2022 09:56:51 -0700 (PDT) Message-ID: <1fadd74c-25d0-b9ab-8a06-27a9faa6579b@linaro.org> Date: Fri, 20 May 2022 09:56:50 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH] cgroup: don't queue css_release_work if one already pending Content-Language: en-US To: =?UTF-8?Q?Michal_Koutn=c3=bd?= Cc: Tejun Heo , Hillf Danton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzbot+e42ae441c3b10acf9e9d@syzkaller.appspotmail.com References: <20220412192459.227740-1-tadeusz.struk@linaro.org> <20220414164409.GA5404@blackbody.suse.cz> <20220422100400.GA29552@blackbody.suse.cz> <20220519112319.2455-1-hdanton@sina.com> <25fb057a-077f-b601-dcb7-130071c733db@linaro.org> <489592f6-b783-7bdb-2cc8-0c8e35ebc674@linaro.org> <20220520164255.GB17335@blackbody.suse.cz> From: Tadeusz Struk In-Reply-To: <20220520164255.GB17335@blackbody.suse.cz> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/20/22 09:42, Michal Koutný wrote: > On Fri, May 20, 2022 at 09:38:12AM -0700, Tadeusz Struk wrote: >> as this is a result of enqueuing the same css->destroy_work onto the same WQ, >> one on the rcu path and one on the css_release path. >> I will prototype it today and test with syzbot. > In my understanding, you'd need two independent work_structs in a css, > not two separate workqueues to put the single entry on. I think either way would work, but two workqueues would be less churn. I can try both. -- Thanks, Tadeusz