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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 448A5C433FE for ; Wed, 20 Oct 2021 11:14:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E80861373 for ; Wed, 20 Oct 2021 11:14:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230105AbhJTLQ4 (ORCPT ); Wed, 20 Oct 2021 07:16:56 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:4008 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229864AbhJTLQz (ORCPT ); Wed, 20 Oct 2021 07:16:55 -0400 Received: from fraeml706-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4HZ7FG37HVz6896K; Wed, 20 Oct 2021 19:10:26 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml706-chm.china.huawei.com (10.206.15.55) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.15; Wed, 20 Oct 2021 13:14:40 +0200 Received: from [10.202.227.179] (10.202.227.179) 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 15.1.2308.15; Wed, 20 Oct 2021 12:14:39 +0100 Subject: Re: [PATCHSET v3] Batched completions To: Jens Axboe , References: <20211017020623.77815-1-axboe@kernel.dk> CC: "linux-scsi@vger.kernel.org" From: John Garry Message-ID: Date: Wed, 20 Oct 2021 12:14:37 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <20211017020623.77815-1-axboe@kernel.dk> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.179] X-ClientProxiedBy: lhreml748-chm.china.huawei.com (10.201.108.198) 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 17/10/2021 03:06, Jens Axboe wrote: > Hi, +linux-scsi > > We now do decent batching of allocations for submit, but we still > complete requests individually. This costs a lot of CPU cycles. > > This patchset adds support for collecting requests for completion, > and then completing them as a batch. This includes things like freeing > a batch of tags. > > This version is looking pretty good to me now, and should be ready > for 5.16. Just wondering if anyone was looking at supporting this for SCSI midlayer? I was thinking about looking at it... > > Changes since v2: > - Get rid of dev_id > - Get rid of mq_ops->complete_batch > - Drop now unnecessary ib->complete setting in blk_poll() > - Drop one sbitmap patch that was questionnable > - Rename io_batch to io_comp_batch > - Track need_timestamp on per-iob basis instead of for each request > - Drop elevator support for batching, cleaner without > - Make the batched driver addition simpler > - Unify nvme polled/irq handling > - Drop io_uring file checking, no longer neededd > - Cleanup io_uring completion side >