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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 CFC19C3F2CD for ; Fri, 28 Feb 2020 19:29:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A25BD2469F for ; Fri, 28 Feb 2020 19:29:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="Adsb6Ufk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725900AbgB1T3A (ORCPT ); Fri, 28 Feb 2020 14:29:00 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:42406 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725730AbgB1T3A (ORCPT ); Fri, 28 Feb 2020 14:29:00 -0500 Received: by mail-pg1-f195.google.com with SMTP id h8so2003141pgs.9 for ; Fri, 28 Feb 2020 11:28:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=LaATqR53L10vg9e7CqVCO27EW8JSFqLY61WZoEOG64E=; b=Adsb6UfkZRmFST2RkDcSEfET6MTzFnbhK49I5IH+sZ5CSEj1yNK4w21Wi7J5duMxTe DllRlABn4RyXkzwfRTMb3Q7rXBYreU9f9DaHW/Gbo6b+5hPZP11G44J8QqRjVhapY4gl UcFM+Lt45PC9e5LYOEjfoV8TiNLRMzlXAbxAUDH6dyNswPnrWk+r9d+reDoZ04Uqbltf kQKdIlBCi7uQpnu1KA7Y/wxWGI04PA2AIyLpeDZojz2ap4biP8vyCmFeN6zHQ/PJXo+O G9HF2yyrIK2ei/EeNJQXF+PDbRLaebBd7U9A8yBYAIo3PbaJq/yP/USdDrKhr9c5d0co ObVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=LaATqR53L10vg9e7CqVCO27EW8JSFqLY61WZoEOG64E=; b=tV3qULxdx58y4YhUP7DZcKWyZ/x+Q32yEaH6Swxr1yNWCozbe1UwIxSDnnK9FmkaGQ X1aiI8d8PjcovEANzVV+NruFEGkhTF3WhCsGsVQk5RGSW0tVeQk4EzAaStomu5Y0PII/ jnSHD/dKoOMHt+BdvwbulFXapmDBcai1Q0N3Dh/5GUsXEoWXQvjrcZ7AEYusZ4pxEfdC TgbOsrLV5NztXmsdC1PjIUCBex0WQ3cKrZsZSF250JYO3fhCRTsZYYsF/ziegoFDIW5d 7pAamrujgsRRdfgZujx8HbbO5E8sSujYIjT4ObjoQJUK95rG3cSqmt33VE681J2tWFG9 BB/Q== X-Gm-Message-State: APjAAAV73CIoopMkNgf0cNp76Egc4hXEERxDSrOk7yStpEvRb1ylnes7 FXLE/N/9G2DmEXP2hakYN7MsftFgwCk= X-Google-Smtp-Source: APXvYqzmPT1BVvviJRxxO8Q5MgcJeVVXkir4w4yxFVc8/1ske3o+IdHz3er9nVqGhcPD0rJT3My+gQ== X-Received: by 2002:a63:b949:: with SMTP id v9mr5867375pgo.336.1582918137115; Fri, 28 Feb 2020 11:28:57 -0800 (PST) Received: from ?IPv6:2620:10d:c085:21d6::12c6? ([2620:10d:c090:400::5:410c]) by smtp.gmail.com with ESMTPSA id e1sm12056223pff.188.2020.02.28.11.28.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 28 Feb 2020 11:28:56 -0800 (PST) Subject: Re: [PATCH] task_work_run: don't take ->pi_lock unconditionally To: Peter Zijlstra Cc: Oleg Nesterov , =?UTF-8?B?Q2FydGVyIExpIOadjumAmua0sg==?= , Pavel Begunkov , io-uring References: <20200218131310.GZ14914@hirez.programming.kicks-ass.net> <20200218145645.GB3466@redhat.com> <20200218150756.GC14914@hirez.programming.kicks-ass.net> <20200218155017.GD3466@redhat.com> <20200220163938.GA18400@hirez.programming.kicks-ass.net> <20200220172201.GC27143@redhat.com> <20200220174932.GB18400@hirez.programming.kicks-ass.net> <20200221145256.GA16646@redhat.com> <77349a8d-ecbf-088d-3a48-321f68f1774f@kernel.dk> <20200228192505.GO18400@hirez.programming.kicks-ass.net> From: Jens Axboe Message-ID: <4c320163-cb3b-8070-4441-6395c988d55d@kernel.dk> Date: Fri, 28 Feb 2020 12:28:54 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200228192505.GO18400@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 2/28/20 12:25 PM, Peter Zijlstra wrote: > On Fri, Feb 28, 2020 at 12:17:58PM -0700, Jens Axboe wrote: >>> >>> Peter/Oleg, as you've probably noticed, I'm still hauling Oleg's >>> original patch around. Is the above going to turn into a separate patch >>> on top? If so, feel free to shove it my way as well for some extra >>> testing. >> >> Peter/Oleg, gentle ping on this query. I'd like to queue up the task poll >> rework on the io_uring side, but I still have this one at the start of >> the series: > > the generic try_cmpxchg crud I posted earlier is 'wrong' and the sane > version I cooked up depends on a whole bunch of patches that are in > limbo because of kcsan (I need to get that resolved one way or the > other). > > So if you don't mind, I'll shelf this for a while until I got all that > sorted. Shelf the one I have queued up, or the suggested changes that you had for on top of it? -- Jens Axboe