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=-5.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 E05D1C433E0 for ; Tue, 2 Jun 2020 09:15:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF34C206C3 for ; Tue, 2 Jun 2020 09:15:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="hLDlUEwh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726217AbgFBJPW (ORCPT ); Tue, 2 Jun 2020 05:15:22 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:30117 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726174AbgFBJPV (ORCPT ); Tue, 2 Jun 2020 05:15:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591089320; 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=qMrQ4R1tiZ47KbGCJ++c4QAwStEuwv3FF+UcNLv0ce0=; b=hLDlUEwhkG/bwI7/lkAE69+UTpNHuNfS+eOmNdHx1rf62tUPLtFzjkjDsL+p+y6GEvBM03 ECS0JZUSjGcR32WwT9WOvNNJ5xvgDnmzYnD+TZ5xzyKCEsobOy8puTs+roFXGC5DBWfhcW OAjfWAQXTVIqMLR9Bt/5ZsRDDdAc2cY= 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-13-tYgeqOAEP7yro0rdLhzozQ-1; Tue, 02 Jun 2020 05:15:15 -0400 X-MC-Unique: tYgeqOAEP7yro0rdLhzozQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B5BE9835B47; Tue, 2 Jun 2020 09:15:13 +0000 (UTC) Received: from localhost (ovpn-12-167.pek2.redhat.com [10.72.12.167]) by smtp.corp.redhat.com (Postfix) with ESMTP id E44736C77F; Tue, 2 Jun 2020 09:15:09 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , Sagi Grimberg , Baolin Wang , Christoph Hellwig Subject: [PATCH V4 0/6] blk-mq: support batching dispatch from scheduler Date: Tue, 2 Jun 2020 17:14:56 +0800 Message-Id: <20200602091502.1822499-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 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 previous versions 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/ V4: - fix releasing budgets and avoids IO hang(5/6) - dispatch more batches if the device can accept more(6/6) - verified by running more tests 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 | 116 +++++++++++++++++++++++++++++++++++----- 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, 187 insertions(+), 71 deletions(-) Cc: Sagi Grimberg Cc: Baolin Wang Cc: Christoph Hellwig -- 2.25.2