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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 4FCEFC433DF for ; Tue, 26 May 2020 20:46:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F966207D8 for ; Tue, 26 May 2020 20:46:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="SK/j8/sB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404089AbgEZUqT (ORCPT ); Tue, 26 May 2020 16:46:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403895AbgEZUqS (ORCPT ); Tue, 26 May 2020 16:46:18 -0400 Received: from mail-qv1-xf43.google.com (mail-qv1-xf43.google.com [IPv6:2607:f8b0:4864:20::f43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 907FEC03E96D for ; Tue, 26 May 2020 13:46:17 -0700 (PDT) Received: by mail-qv1-xf43.google.com with SMTP id f89so10164318qva.3 for ; Tue, 26 May 2020 13:46:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=grxbOYNpOqxM7JP5izyFEjnzTirkS5+MQpdVDhkVv6s=; b=SK/j8/sBEAECUReC3/26qb5WYBKgJusmM4Bi0ypDM/Zohzcal6XacR3hCU754mhVtt E/5T4evfDsYZZhA9Ukgqn71YcrmQhklo/ouZh7stq4wCar8JR0/8bulocC1KxQxwmqk3 DDp4qVL9jeoL9CohXbQhdUV/7gnfjQAqnufAqXJl5p1ZSF5aNK8Xc0r/slhNtqDf96z7 RPlr9aVuPCFMtPtrndIWOuD20FaYhurPZLBbVrBcYvb4pSG0il+Tfmct4CaGWVG06Mc8 HQMn28HfZJDmqy7v+pNpgsdZwJeG0NcquoKR0QGCX0ZPO54EuyQMmtsgW7QGQr8jRLP1 hbNA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=grxbOYNpOqxM7JP5izyFEjnzTirkS5+MQpdVDhkVv6s=; b=O2liNjza7n+6xVtU0wUobxJxGVcTBJAeFJaFiY0C/hiUpR0lR0XvEGN9M1F0rg3HGd fm5W3Y4uYSRfQz/av4LhdN1ulN+lmaWAklREKBKwp6x/V8Ov0skzP71yJV7hwQjfnBpG JOD2iHQAckzADFKts/FV2kFmlDTsX308cDx+UsuxGDWFpvmXFFp0ADFu3x17fyAw4IF8 bl/uMSikWbggRxZnPBpPBdrdhehbgB2zYK3YWDvarqhVMB1Nflz3RT93xsVikmLV3NNw C+aF8MdVSqwsjJPYLZPyIyEBr3STrt6X7m0Xjgb1PLdv2ANWP8ZwGoHMG73lxe/5cvTE Th7w== X-Gm-Message-State: AOAM532xgnHH/xiwY0lpJwoS7PwoQUMcevg1TICjO8JzILJJNVQ3Jo+k 3STrhxjRf2iKn3UuDgGSTUU4DwbclqE= X-Google-Smtp-Source: ABdhPJw17yp0oF4CQ8J3+E7IWKM6xulkRGgACyehYTnS6SFzVDCaB8Ziav9WNv6ap066m6W/aJRucA== X-Received: by 2002:a0c:ffc6:: with SMTP id h6mr8896151qvv.213.1590525976662; Tue, 26 May 2020 13:46:16 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:2921]) by smtp.gmail.com with ESMTPSA id n184sm658331qkf.0.2020.05.26.13.46.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 May 2020 13:46:15 -0700 (PDT) Date: Tue, 26 May 2020 16:45:52 -0400 From: Johannes Weiner To: Jens Axboe Cc: io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org Subject: Re: [PATCH 02/12] mm: allow read-ahead with IOCB_NOWAIT set Message-ID: <20200526204552.GA6781@cmpxchg.org> References: <20200526195123.29053-1-axboe@kernel.dk> <20200526195123.29053-3-axboe@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200526195123.29053-3-axboe@kernel.dk> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 26, 2020 at 01:51:13PM -0600, Jens Axboe wrote: > The read-ahead shouldn't block, so allow it to be done even if > IOCB_NOWAIT is set in the kiocb. > > Signed-off-by: Jens Axboe Acked-by: Johannes Weiner Looks reasonable. Especially after patch 1 - although it seems that even before that, IOCB_NOWAIT could have occasionally ended up in page_cache_async_readahead(), which isn't too different from the sync variant except for the range calculations, and may have blocked on IO submission in the past.