From patchwork Mon Nov 16 09:07:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 11907797 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 97C221391 for ; Mon, 16 Nov 2020 09:08:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69FF92224F for ; Mon, 16 Nov 2020 09:08:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OM8rQ4zu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728348AbgKPJH4 (ORCPT ); Mon, 16 Nov 2020 04:07:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26619 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728064AbgKPJH4 (ORCPT ); Mon, 16 Nov 2020 04:07:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605517674; 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=8iYl59OX23WRKS1JfS8R+a2mr+6QlmFy8JxMpR5laRs=; b=OM8rQ4zuR1aj608QSBmr54w0kzokIExWe6u5rZjqFjmFpdyuhAfnv0VSmCU8HbuijoBvAd AvTqLAsx9voNjH0wxFouNu56IVu4O1ismDcA6FKhF+4qIHe9pWi6X8K2vkqhTmxp8wLeJ+ YcfW1gOIeWkCwtjRokVlyupD+3SrPrQ= 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-193-igxyXnWFNcmolh_iNf0kXw-1; Mon, 16 Nov 2020 04:07:50 -0500 X-MC-Unique: igxyXnWFNcmolh_iNf0kXw-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 4DE25800683; Mon, 16 Nov 2020 09:07:48 +0000 (UTC) Received: from localhost (ovpn-13-166.pek2.redhat.com [10.72.13.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 08A1A6EF42; Mon, 16 Nov 2020 09:07:43 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org, "Martin K . Petersen" , linux-scsi@vger.kernel.org Cc: Ming Lei , Omar Sandoval , Kashyap Desai , Sumanesh Samanta , "Ewan D . Milne" , Hannes Reinecke Subject: [PATCH V4 00/12] blk-mq/scsi: tracking device queue depth via sbitmap Date: Mon, 16 Nov 2020 17:07:25 +0800 Message-Id: <20201116090737.50989-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi, scsi uses one global atomic variable to track queue depth for each LUN/request queue. This way can't scale well when there is lots of CPU cores and the disk is very fast. Broadcom guys has complained that their high end HBA can't reach top performance because .device_busy is operated in IO path. Replace the atomic variable sdev->device_busy with sbitmap for tracking scsi device queue depth. Test on scsi_debug shows this way improve IOPS > 20%. Meantime the IOPS difference is just ~1% compared with bypassing .device_busy on scsi_debug via patches[1] The 1st 6 patches moves percpu allocation hint into sbitmap, since the improvement by doing percpu allocation hint on sbitmap is observable. Meantime export helpers for SCSI. Patch 7 and 8 prepares for the conversion by returning budget token from .get_budget callback, meantime passes the budget token to driver via 'struct blk_mq_queue_data' in .queue_rq(). The last four patches changes SCSI for switching to track device queue depth via sbitmap. The patchset have been tested by Broadcom, and obvious performance boost can be observed. https://github.com/ming1/linux/tree/v5.10-block-replace-sdev-device_busy-with-sbitmap V4: - limit max sdev->queue_depth as max(1024, shost->can_queue) - simplify code for moving per-cpu allocation hint into sbitmap V3: - rebase on both for-5.10/block and 5.10/scsi-queue. V2: - fix one build failure Ming Lei (12): sbitmap: remove sbitmap_clear_bit_unlock sbitmap: maintain allocation round_robin in sbitmap sbitmap: add helpers for updating allocation hint sbitmap: move allocation hint into sbitmap sbitmap: export sbitmap_weight sbitmap: add helper of sbitmap_calculate_shift blk-mq: add callbacks for storing & retrieving budget token blk-mq: return budget token from .get_budget callback scsi: put hot fields of scsi_host_template into one cacheline scsi: add scsi_device_busy() to read sdev->device_busy scsi: make sure sdev->queue_depth is <= max(shost->can_queue, 1024) scsi: replace sdev->device_busy with sbitmap block/blk-mq-sched.c | 17 ++- block/blk-mq.c | 38 +++-- block/blk-mq.h | 25 +++- block/kyber-iosched.c | 3 +- drivers/message/fusion/mptsas.c | 2 +- drivers/scsi/mpt3sas/mpt3sas_scsih.c | 2 +- drivers/scsi/scsi.c | 13 ++ drivers/scsi/scsi_lib.c | 69 ++++++--- drivers/scsi/scsi_priv.h | 3 + drivers/scsi/scsi_scan.c | 23 ++- drivers/scsi/scsi_sysfs.c | 4 +- drivers/scsi/sg.c | 2 +- include/linux/blk-mq.h | 13 +- include/linux/sbitmap.h | 84 +++++++---- include/scsi/scsi_cmnd.h | 2 + include/scsi/scsi_device.h | 8 +- include/scsi/scsi_host.h | 72 ++++----- lib/sbitmap.c | 210 +++++++++++++++------------ 18 files changed, 385 insertions(+), 205 deletions(-) Cc: Omar Sandoval Cc: Kashyap Desai Cc: Sumanesh Samanta Cc: Ewan D. Milne Cc: Hannes Reinecke