From patchwork Tue Feb 11 12:11:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 11375265 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 859FC921 for ; Tue, 11 Feb 2020 12:12:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62B5F206DB for ; Tue, 11 Feb 2020 12:12:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="afLGfgzi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728308AbgBKMMA (ORCPT ); Tue, 11 Feb 2020 07:12:00 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:58367 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728294AbgBKML7 (ORCPT ); Tue, 11 Feb 2020 07:11:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581423118; 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=V+9xBTZc7bbwJTMVnkz3jGlnFUdab8OBec7wzgQHg/M=; b=afLGfgzihNLaK7LNqB83JWyZg5WottUzJTRo/mxBNJCtw/JeRdd57AeYxx79QIlIaWFrqf rXjCKDjL1yWwp7mVnN9UgckbrmvKnI0TaSw5ichZsbZ1gQsleEepstnItz0PPFSgCinYp/ 7I8WA1W+R5LcsoGSElDnezg+ZtMnNZc= 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-204-gxJknGH-PsSc104LB1CEug-1; Tue, 11 Feb 2020 07:11:52 -0500 X-MC-Unique: gxJknGH-PsSc104LB1CEug-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BD3FB8017CC; Tue, 11 Feb 2020 12:11:49 +0000 (UTC) Received: from localhost (ovpn-8-17.pek2.redhat.com [10.72.8.17]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3E2E05C1D6; Tue, 11 Feb 2020 12:11:45 +0000 (UTC) From: Ming Lei To: James Bottomley , linux-scsi@vger.kernel.org, "Martin K . Petersen" , linux-block@vger.kernel.org, Jens Axboe Cc: Ming Lei , Omar Sandoval , Sathya Prakash , Chaitra P B , Suganath Prabu Subramani , Kashyap Desai , Sumit Saxena , Shivasharan S , "Ewan D . Milne" , Hannes Reinecke , Bart Van Assche Subject: [PATCH 00/10] scsi: tracking device queue depth via sbitmap Date: Tue, 11 Feb 2020 20:11:25 +0800 Message-Id: <20200211121135.30064-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: linux-scsi-owner@vger.kernel.org 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 two patches changes SCSI for switching to track device queue depth via sbitmap. Broadcom Guys, please test this patchset and see if expected performance can be reached. Please comment and review! thanks, Ming [1] https://lore.kernel.org/linux-block/20200119071432.18558-6-ming.lei@redhat.com/ Ming Lei (10): sbitmap: maintain allocation round_robin in sbitmap sbitmap: add helpers for updating allocation hint sbitmap: remove sbitmap_clear_bit_unlock sbitmap: move allocation hint into sbitmap sbitmap: export sbitmap_weight sbitmap: add helper of sbitmap_calculate_shift blk-mq: return budget token from .get_budget callback blk-mq: pass budget token to dirver via blk_mq_queue_data scsi: add scsi_device_busy() to read sdev->device_busy scsi: replace sdev->device_busy with sbitmap block/blk-mq-sched.c | 20 ++- block/blk-mq.c | 37 +++-- block/blk-mq.h | 11 +- block/kyber-iosched.c | 3 +- drivers/dma/idxd/device.c | 2 +- drivers/dma/idxd/submit.c | 2 +- drivers/scsi/mpt3sas/mpt3sas_scsih.c | 2 +- drivers/scsi/scsi.c | 2 + drivers/scsi/scsi_lib.c | 47 +++--- drivers/scsi/scsi_priv.h | 1 + drivers/scsi/scsi_scan.c | 21 ++- drivers/scsi/scsi_sysfs.c | 4 +- drivers/scsi/sg.c | 2 +- include/linux/blk-mq.h | 5 +- include/linux/sbitmap.h | 84 +++++++---- include/scsi/scsi_cmnd.h | 2 + include/scsi/scsi_device.h | 8 +- lib/sbitmap.c | 213 +++++++++++++++------------ 18 files changed, 285 insertions(+), 181 deletions(-) Cc: Omar Sandoval Cc: Sathya Prakash Cc: Chaitra P B Cc: Suganath Prabu Subramani Cc: Kashyap Desai Cc: Sumit Saxena Cc: Shivasharan S Cc: Ewan D. Milne Cc: Hannes Reinecke Cc: Bart Van Assche