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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 9ED9CC46471 for ; Tue, 7 Aug 2018 07:21:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FFFA219DB for ; Tue, 7 Aug 2018 07:21:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FFFA219DB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de 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 S2388814AbeHGJen (ORCPT ); Tue, 7 Aug 2018 05:34:43 -0400 Received: from verein.lst.de ([213.95.11.211]:59658 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727360AbeHGJen (ORCPT ); Tue, 7 Aug 2018 05:34:43 -0400 Received: by newverein.lst.de (Postfix, from userid 2407) id 7F0A668D62; Tue, 7 Aug 2018 09:27:02 +0200 (CEST) Date: Tue, 7 Aug 2018 09:27:02 +0200 From: Christoph Hellwig To: Linus Torvalds Cc: Christoph Hellwig , Al Viro , Avi Kivity , linux-aio@kvack.org, linux-fsdevel , Linux Kernel Mailing List Subject: Re: aio poll V22 (aka 2.0) Message-ID: <20180807072702.GB678@lst.de> References: <20180806083058.14724-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 06, 2018 at 09:49:24AM -0700, Linus Torvalds wrote: > I'm not seeing what's painful for this. Looking at the patches, this > is *much* more straightforward than your previous patch, > > It adds refcounting to aio_iocb, but that's *much* better than messing > up every other subsystem. > > Or is there some follow-up patches that are pending but you didn't > post that are the painful part? Because the diffstat says that this > second version is *way* less painful, at about 200 lines of code in a > couple of files, mostly aio, vs ~700 lines of changes all over the > place, together with a performance regression. It requires additional lock roundtrips and very strange life time rules. But we've already established that our preference here are different, so I'm not surprised by your different view.