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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 5133CC07E9B for ; Wed, 7 Jul 2021 15:38:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34A62619C6 for ; Wed, 7 Jul 2021 15:38:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231786AbhGGPli (ORCPT ); Wed, 7 Jul 2021 11:41:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231639AbhGGPlh (ORCPT ); Wed, 7 Jul 2021 11:41:37 -0400 Received: from mail-oi1-x22a.google.com (mail-oi1-x22a.google.com [IPv6:2607:f8b0:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 481AAC06175F for ; Wed, 7 Jul 2021 08:38:57 -0700 (PDT) Received: by mail-oi1-x22a.google.com with SMTP id w127so3783237oig.12 for ; Wed, 07 Jul 2021 08:38:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=H/u+AYAwK9mJcG4oUWcnUGsuenx4nlYeOD13u9gKYw4=; b=hBe29YUOrYgfT6USN8t15IXPOdsaxaWTgbrLieT0ub7LIuxZQLgx28SKSKI2NneYaX 3TfqswY3vdTXnPYj/gn7E2GPnw3fzQoZ4/2cKo2U8yYmk5UOaMGBZQV4FkLxJmLZXtVU WvhFUSJeZJD0jCIgSkOooNBIcaNQ9PF6I4tHzvnb41Q+vpQ2njGA69DOrhrmQUVwdRRi Sh9D/0WnPlX9q+V7H0eoW9RNCAufgJnb+iMaMGxTsP5RGsfxe2RomDZSsmI9qPJ6eHFr 413hVjj1elDDIYi4tiXFVKvlOELXOGD7sQNBIzlhRADjBFfQJmRxGkGU8TIJv3VJCVld rESw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=H/u+AYAwK9mJcG4oUWcnUGsuenx4nlYeOD13u9gKYw4=; b=GLdksPRdbJ93Q96cQruk6OtGY21/Ba/MrvV233BSyRt5sG1VqmF8Y1JqxgxkRAbzZR jM0GD3VB+9Oke9JxIaTONS24sJx//+1YfaKWLVuF9U88W9qOnQNBBZuFB5NLT4/6jqRb mgjl3bPyhXQbncwPep+nCYv12Kgki4kgv2mCWzn02pOmaecUBLTgmYevomHzCPqsUoYH fgpKTfxT2KbDI3pWsFnybbUBVzPQ2NAu+ffxZjQtvhfRaSmslmclSwXt+ntLRffZP0KK LoQFRhVel25t1tPHpErpcPpEhowWieZCvaoF1el1Y3+PYy+6d//YDQnR6vHVccL0QgfA E9qw== X-Gm-Message-State: AOAM532RJ950vb3iMmKu3ikPZwEkKZEvKkHutUaeYxIucsIyyW4hyHMm jegX+eBiwbmav1FI+m3dRu/zjg== X-Google-Smtp-Source: ABdhPJxfpHgxHg2b3kqBMIvAO3jc3igdIVCQdUBIWCICtzLhDSXduDYBwRAIqIfJAgkrJZQnFRiyqg== X-Received: by 2002:aca:d641:: with SMTP id n62mr154422oig.77.1625672336548; Wed, 07 Jul 2021 08:38:56 -0700 (PDT) Received: from [192.168.1.170] ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id o189sm4241409oif.54.2021.07.07.08.38.55 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 07 Jul 2021 08:38:56 -0700 (PDT) Subject: Re: [PATCH V2] blk-cgroup: prevent rcu_sched detected stalls warnings while iterating blkgs To: Yu Kuai , tj@kernel.org Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com References: <20210707015649.1929797-1-yukuai3@huawei.com> From: Jens Axboe Message-ID: Date: Wed, 7 Jul 2021 09:38:54 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210707015649.1929797-1-yukuai3@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/6/21 7:56 PM, Yu Kuai wrote: > We run a test that create millions of cgroups and blkgs, and then trigger > blkg_destroy_all(). blkg_destroy_all() will hold spin lock for a long > time in such situation. Thus release the lock when a batch of blkgs are > destroyed. > > blkcg_activate_policy() and blkcg_deactivate_policy() might have the > same problem, however, as they are basically only called from module > init/exit paths, let's leave them alone for now. Applied, thanks. -- Jens Axboe