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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 95F9BC00449 for ; Tue, 9 Oct 2018 02:49:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 545B7213A2 for ; Tue, 9 Oct 2018 02:49:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 545B7213A2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726810AbeJIKEb (ORCPT ); Tue, 9 Oct 2018 06:04:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60770 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726616AbeJIKEb (ORCPT ); Tue, 9 Oct 2018 06:04:31 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 09FE785550; Tue, 9 Oct 2018 02:49:50 +0000 (UTC) Received: from ming.t460p (ovpn-8-19.pek2.redhat.com [10.72.8.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ADAC11054FBA; Tue, 9 Oct 2018 02:49:43 +0000 (UTC) Date: Tue, 9 Oct 2018 10:49:38 +0800 From: Ming Lei To: Jianchao Wang Cc: axboe@kernel.dk, keith.busch@linux.intel.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] blk-mq: adjust debugfs and sysfs register when updating nr_hw_queues Message-ID: <20181009024937.GA18673@ming.t460p> References: <1538044984-2147-1-git-send-email-jianchao.w.wang@oracle.com> <1538044984-2147-2-git-send-email-jianchao.w.wang@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1538044984-2147-2-git-send-email-jianchao.w.wang@oracle.com> User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 09 Oct 2018 02:49:50 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 27, 2018 at 06:43:03PM +0800, Jianchao Wang wrote: > blk-mq debugfs and sysfs entries need to be removed before updating > queue map, otherwise, we get get wrong result there. This patch fixes > it and remove the redundant debugfs and sysfs register/unregister > operations during __blk_mq_update_nr_hw_queues. > > Signed-off-by: Jianchao Wang > --- > block/blk-mq.c | 39 ++++++++++++--------------------------- > 1 file changed, 12 insertions(+), 27 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 85a1c1a..6356455 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -2137,8 +2137,6 @@ static void blk_mq_exit_hctx(struct request_queue *q, > struct blk_mq_tag_set *set, > struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) > { > - blk_mq_debugfs_unregister_hctx(hctx); > - > if (blk_mq_hw_queue_mapped(hctx)) > blk_mq_tag_idle(hctx); > > @@ -2165,6 +2163,7 @@ static void blk_mq_exit_hw_queues(struct request_queue *q, > queue_for_each_hw_ctx(q, hctx, i) { > if (i == nr_queue) > break; > + blk_mq_debugfs_unregister_hctx(hctx); > blk_mq_exit_hctx(q, set, hctx, i); > } > } > @@ -2222,8 +2221,6 @@ static int blk_mq_init_hctx(struct request_queue *q, > if (hctx->flags & BLK_MQ_F_BLOCKING) > init_srcu_struct(hctx->srcu); > > - blk_mq_debugfs_register_hctx(q, hctx); > - > return 0; > > free_fq: > @@ -2512,8 +2509,6 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, > int i, j; > struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; > > - blk_mq_sysfs_unregister(q); > - > /* protect against switching io scheduler */ > mutex_lock(&q->sysfs_lock); > for (i = 0; i < set->nr_hw_queues; i++) { > @@ -2561,7 +2556,6 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, > } > q->nr_hw_queues = i; > mutex_unlock(&q->sysfs_lock); > - blk_mq_sysfs_register(q); > } > > struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, > @@ -2659,25 +2653,6 @@ void blk_mq_free_queue(struct request_queue *q) > blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); > } > > -/* Basically redo blk_mq_init_queue with queue frozen */ > -static void blk_mq_queue_reinit(struct request_queue *q) > -{ > - WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); > - > - blk_mq_debugfs_unregister_hctxs(q); > - blk_mq_sysfs_unregister(q); > - > - /* > - * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe > - * we should change hctx numa_node according to the new topology (this > - * involves freeing and re-allocating memory, worth doing?) > - */ > - blk_mq_map_swqueue(q); > - > - blk_mq_sysfs_register(q); > - blk_mq_debugfs_register_hctxs(q); > -} > - > static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) > { > int i; > @@ -2987,11 +2962,21 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, > if (!blk_mq_elv_switch_none(&head, q)) > goto switch_back; > > + list_for_each_entry(q, &set->tag_list, tag_set_list) { > + blk_mq_debugfs_unregister_hctxs(q); > + blk_mq_sysfs_unregister(q); > + } > + > set->nr_hw_queues = nr_hw_queues; > blk_mq_update_queue_map(set); > list_for_each_entry(q, &set->tag_list, tag_set_list) { > blk_mq_realloc_hw_ctxs(set, q); > - blk_mq_queue_reinit(q); > + blk_mq_map_swqueue(q); > + } > + > + list_for_each_entry(q, &set->tag_list, tag_set_list) { > + blk_mq_sysfs_register(q); > + blk_mq_debugfs_register_hctxs(q); > } > > switch_back: > -- > 2.7.4 > Reviewed-by: Ming Lei Thanks, Ming