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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 96C67C2BC11 for ; Fri, 11 Sep 2020 09:53:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 589962078B for ; Fri, 11 Sep 2020 09:53:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725554AbgIKJxE (ORCPT ); Fri, 11 Sep 2020 05:53:04 -0400 Received: from verein.lst.de ([213.95.11.211]:36286 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725710AbgIKJxB (ORCPT ); Fri, 11 Sep 2020 05:53:01 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 4C59B68B02; Fri, 11 Sep 2020 11:52:58 +0200 (CEST) Date: Fri, 11 Sep 2020 11:52:58 +0200 From: Christoph Hellwig To: Ming Lei Cc: Jens Axboe , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, Christoph Hellwig , David Milburn , "Ewan D . Milne" Subject: Re: [PATCH] blk-mq: always allow reserved allocation in hctx_may_queue Message-ID: <20200911095258.GA914@lst.de> References: <20200911094453.160109-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200911094453.160109-1-ming.lei@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Sep 11, 2020 at 05:44:53PM +0800, Ming Lei wrote: > unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags; > int tag; > + bool reserved = blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, > + rq->internal_tag); > > blk_mq_tag_busy(rq->mq_hctx); > > - if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) { > + if (reserved) { > bt = rq->mq_hctx->tags->breserved_tags; > tag_offset = 0; > } > > - if (!hctx_may_queue(rq->mq_hctx, bt)) > + if (!reserved && !hctx_may_queue(rq->mq_hctx, bt)) What about: if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) { bt = rq->mq_hctx->tags->breserved_tags; tag_offset = 0; } else { if (!hctx_may_queue(rq->mq_hctx, bt)) return false; } which seems a little easier to follow? Otherwise looks good: Reviewed-by: Christoph Hellwig