From patchwork Thu May 28 08:00:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 11575235 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1729E60D for ; Thu, 28 May 2020 08:01:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F396821508 for ; Thu, 28 May 2020 08:01:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="L7pxlj7E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725839AbgE1IBQ (ORCPT ); Thu, 28 May 2020 04:01:16 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:55987 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725901AbgE1IBP (ORCPT ); Thu, 28 May 2020 04:01:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590652874; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=PbJoT2F2lFRbK3iDIBBxpGnGYKEW9Z+Ntt/XK5EwBqs=; b=L7pxlj7EZBOpPQRvZZyd31mH1qpvfQSxLhvc71c5v6bKfb4MLHZLaT6aTDAZ16r7Vcda38 nCn4n4seO1uBJpJiBkjQEs6Yo5+vtoKkGcZDiA3FL5UgtPMprU+AEa2osfjA20wzucr79/ AIwiypz3Wjjpyc4A0N1d8zyiSe4ohJE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-430-ioCAz0LJPCef8TEk8gJ8Rg-1; Thu, 28 May 2020 04:01:08 -0400 X-MC-Unique: ioCAz0LJPCef8TEk8gJ8Rg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1261580183C; Thu, 28 May 2020 08:01:07 +0000 (UTC) Received: from localhost (ovpn-12-189.pek2.redhat.com [10.72.12.189]) by smtp.corp.redhat.com (Postfix) with ESMTP id 72F90D01E0; Thu, 28 May 2020 08:01:03 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , Sagi Grimberg , Baolin Wang , Christoph Hellwig Subject: [PATCH V3 0/6] blk-mq: support batching dispatch from scheduler Date: Thu, 28 May 2020 16:00:47 +0800 Message-Id: <20200528080053.1062653-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi Jens, More and more drivers want to get batching requests queued from block layer, such as mmc[1], and tcp based storage drivers[2]. Also current in-tree users have virtio-scsi, virtio-blk and nvme. For none, we already support batching dispatch. But for io scheduler, every time we just take one request from scheduler and pass the single request to blk_mq_dispatch_rq_list(). This way makes batching dispatch not possible when io scheduler is applied. One reason is that we don't want to hurt sequential IO performance, becasue IO merge chance is reduced if more requests are dequeued from scheduler queue. Tries to start the support by dequeuing more requests from scheduler if budget is enough and device isn't busy. Simple fio test over virtio-scsi shows IO can get improved by 5~10%. Baolin has tested V1 and found performance on MMC can be improved. Patches can be found from the following tree too: https://github.com/ming1/linux/commits/v5.7-rc-blk-mq-batching-submission Patch 1 ~ 4 are improvement and cleanup, which can't applied without supporting batching dispatch. Patch 5 ~ 6 starts to support batching dispatch from scheduler. [1] https://lore.kernel.org/linux-block/20200512075501.GF1531898@T590/#r [2] https://lore.kernel.org/linux-block/fe6bd8b9-6ed9-b225-f80c-314746133722@grimberg.me/ V3: - add reviewed-by tag - fix one typo - fix one budget leak issue in case that .queue_rq returned *_RESOURCE in 5/6 V2: - remove 'got_budget' from blk_mq_dispatch_rq_list - drop patch for getting driver tag & handling partial dispatch Ming Lei (6): blk-mq: pass request queue into get/put budget callback blk-mq: pass hctx to blk_mq_dispatch_rq_list blk-mq: move getting driver tag and budget into one helper blk-mq: remove dead check from blk_mq_dispatch_rq_list blk-mq: pass obtained budget count to blk_mq_dispatch_rq_list blk-mq: support batching dispatch in case of io scheduler block/blk-mq-sched.c | 95 ++++++++++++++++++++++++++++----- block/blk-mq.c | 115 ++++++++++++++++++++++++++-------------- block/blk-mq.h | 15 +++--- drivers/scsi/scsi_lib.c | 8 ++- include/linux/blk-mq.h | 4 +- 5 files changed, 168 insertions(+), 69 deletions(-) Cc: Sagi Grimberg Cc: Baolin Wang Cc: Christoph Hellwig Tested-by: Baolin Wang