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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 5BD60C4360C for ; Tue, 8 Oct 2019 10:09:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 322B02070B for ; Tue, 8 Oct 2019 10:09:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730121AbfJHKJz (ORCPT ); Tue, 8 Oct 2019 06:09:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44036 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730106AbfJHKJz (ORCPT ); Tue, 8 Oct 2019 06:09:55 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 853F43060617; Tue, 8 Oct 2019 10:09:55 +0000 (UTC) Received: from localhost (ovpn-8-31.pek2.redhat.com [10.72.8.31]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0C76560BE2; Tue, 8 Oct 2019 10:09:51 +0000 (UTC) From: Ming Lei To: linux-scsi@vger.kernel.org, "Martin K . Petersen" Cc: James Bottomley , Ming Lei , Jens Axboe , "Ewan D . Milne" , Omar Sandoval , James Bottomley , Christoph Hellwig , Kashyap Desai , Hannes Reinecke , Laurence Oberman , Bart Van Assche Subject: [PATCH V3 0/2] scsi: avoid atomic operations in IO path Date: Tue, 8 Oct 2019 18:09:43 +0800 Message-Id: <20191008100945.24951-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Tue, 08 Oct 2019 10:09:55 +0000 (UTC) Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi, The 1st patch kills the atomic host-wide counter of host_busy. The 2nd patch bypass the atomic LUN-wide connter of device_busy for fast SSD device. V3: - use non-atomic set/clear bit operations as suggested by Bart - kill single field struct for storing count of in-flight requests - add patch to bypass the atomic LUN-wide counter of device_busy for fast SSD device V2: - introduce SCMD_STATE_INFLIGHT for getting accurate host busy via blk_mq_tagset_busy_iter() - verified that original Jens's report[1] is fixed - verified that SCSI timeout/abort works fine Ming Lei (2): scsi: core: avoid host-wide host_busy counter for scsi_mq scsi: core: don't limit per-LUN queue depth for SSD drivers/scsi/hosts.c | 19 +++++++++++++- drivers/scsi/scsi.c | 2 +- drivers/scsi/scsi_lib.c | 57 +++++++++++++++++++++++----------------- drivers/scsi/scsi_priv.h | 2 +- include/scsi/scsi_cmnd.h | 1 + include/scsi/scsi_host.h | 1 - 6 files changed, 54 insertions(+), 28 deletions(-) Cc: Jens Axboe Cc: Ewan D. Milne Cc: Omar Sandoval , Cc: "Martin K. Petersen" , Cc: James Bottomley , Cc: Christoph Hellwig , Cc: Kashyap Desai Cc: Hannes Reinecke Cc: Laurence Oberman Cc: Bart Van Assche -- 2.20.1