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, 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 985E1C433B4 for ; Tue, 27 Apr 2021 07:55:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CE85613B4 for ; Tue, 27 Apr 2021 07:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231262AbhD0H4i (ORCPT ); Tue, 27 Apr 2021 03:56:38 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2918 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230325AbhD0H4h (ORCPT ); Tue, 27 Apr 2021 03:56:37 -0400 Received: from fraeml704-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FTv1s6JbXz73dRH; Tue, 27 Apr 2021 15:45:21 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml704-chm.china.huawei.com (10.206.15.53) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Tue, 27 Apr 2021 09:55:53 +0200 Received: from [10.47.94.234] (10.47.94.234) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Tue, 27 Apr 2021 08:55:52 +0100 Subject: Re: [bug report] shared tags causes IO hang and performance drop To: Ming Lei CC: Kashyap Desai , , , "Martin K. Petersen" , Jens Axboe , Douglas Gilbert , Hannes Reinecke References: <87ceccf2-287b-9bd1-899a-f15026c9e65b@huawei.com> <0c85fe52-ebc7-68b3-2dbe-dfad5d604346@huawei.com> <55743a51-4d6f-f481-cebf-e2af9c657911@huawei.com> <9ad15067-ba7b-a335-ae71-8c4328856b91@huawei.com> From: John Garry Message-ID: Date: Tue, 27 Apr 2021 08:52:53 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.94.234] X-ClientProxiedBy: lhreml745-chm.china.huawei.com (10.201.108.195) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 27/04/2021 00:59, Ming Lei wrote: >> Anyway, I'll look at adding code for a per-request queue sched tags to see >> if it helps. But I would plan to continue to use a per hctx sched request >> pool. > Why not switch to per hctx sched request pool? I don't understand. The current code uses a per-hctx sched request pool, and I said that I don't plan to change that. Thanks, John