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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable 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 ED94DC282CF for ; Mon, 28 Jan 2019 14:26:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7C042171F for ; Mon, 28 Jan 2019 14:26:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726749AbfA1O0T (ORCPT ); Mon, 28 Jan 2019 09:26:19 -0500 Received: from verein.lst.de ([213.95.11.211]:39918 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726266AbfA1O0T (ORCPT ); Mon, 28 Jan 2019 09:26:19 -0500 Received: by newverein.lst.de (Postfix, from userid 2407) id 7F49468DCF; Mon, 28 Jan 2019 15:26:18 +0100 (CET) Date: Mon, 28 Jan 2019 15:26:18 +0100 From: Christoph Hellwig To: Jens Axboe Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, linux-block@vger.kernel.org, hch@lst.de, jmoyer@redhat.com, avi@scylladb.com Subject: Re: [PATCH 03/18] block: add bio_set_polled() helper Message-ID: <20190128142618.GB9563@lst.de> References: <20190123153536.7081-1-axboe@kernel.dk> <20190123153536.7081-4-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190123153536.7081-4-axboe@kernel.dk> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Jan 23, 2019 at 08:35:14AM -0700, Jens Axboe wrote: > For the upcoming async polled IO, we can't sleep allocating requests. > If we do, then we introduce a deadlock where the submitter already > has async polled IO in-flight, but can't wait for them to complete > since polled requests must be active found and reaped. > > Utilize the helper in the blockdev DIRECT_IO code. > > Signed-off-by: Jens Axboe Looks good, Reviewed-by: Christoph Hellwig