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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 7A6CCC433B4 for ; Mon, 26 Apr 2021 14:35:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AEA06127A for ; Mon, 26 Apr 2021 14:35:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233471AbhDZOg2 (ORCPT ); Mon, 26 Apr 2021 10:36:28 -0400 Received: from verein.lst.de ([213.95.11.211]:41526 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231862AbhDZOg2 (ORCPT ); Mon, 26 Apr 2021 10:36:28 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 17FA668C4E; Mon, 26 Apr 2021 16:35:44 +0200 (CEST) Date: Mon, 26 Apr 2021 16:35:43 +0200 From: Christoph Hellwig To: Keith Busch Cc: linux-nvme@lists.infradead.org, sagi@grimberg.me, hch@lst.de, axboe@kernel.dk, linux-block@vger.kernel.org, Yuanyuan Zhong , Casey Chen Subject: Re: [PATCHv2 1/5] block: support polling through blk_execute_rq Message-ID: <20210426143543.GA20668@lst.de> References: <20210423220558.40764-1-kbusch@kernel.org> <20210423220558.40764-2-kbusch@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210423220558.40764-2-kbusch@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Apr 23, 2021 at 03:05:54PM -0700, Keith Busch wrote: > Poll for completions if the request's hctx is a polling type. > > Signed-off-by: Keith Busch > --- > block/blk-exec.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/block/blk-exec.c b/block/blk-exec.c > index beae70a0e5e5..b960ad187ba5 100644 > --- a/block/blk-exec.c > +++ b/block/blk-exec.c > @@ -63,6 +63,11 @@ void blk_execute_rq_nowait(struct gendisk *bd_disk, struct request *rq, > } > EXPORT_SYMBOL_GPL(blk_execute_rq_nowait); > > +static bool blk_rq_is_poll(struct request *rq) > +{ > + return rq->mq_hctx && rq->mq_hctx->type == HCTX_TYPE_POLL; > +} > + > /** > * blk_execute_rq - insert a request into queue for execution > * @bd_disk: matching gendisk > @@ -83,7 +88,12 @@ void blk_execute_rq(struct gendisk *bd_disk, struct request *rq, int at_head) > > /* Prevent hang_check timer from firing at us during very long I/O */ > hang_check = sysctl_hung_task_timeout_secs; > - if (hang_check) > + if (blk_rq_is_poll(rq)) { > + do { > + blk_poll(rq->q, request_to_qc_t(rq->mq_hctx, rq), true); > + cond_resched(); > + } while (!completion_done(&wait)); I think it would be nice to split this into a little helper. > + } else if (hang_check) > while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2))); And while we're at it, it would be nice to split this out as well and document this mess..