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_INVALID,DKIM_SIGNED, 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 C1103C04AB4 for ; Tue, 14 May 2019 11:49:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7B29B20843 for ; Tue, 14 May 2019 11:49:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TIFvPOXm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B29B20843 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1119F6B0003; Tue, 14 May 2019 07:49:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0C20A6B0006; Tue, 14 May 2019 07:49:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EF0B76B0007; Tue, 14 May 2019 07:49:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-io1-f69.google.com (mail-io1-f69.google.com [209.85.166.69]) by kanga.kvack.org (Postfix) with ESMTP id D16346B0003 for ; Tue, 14 May 2019 07:49:29 -0400 (EDT) Received: by mail-io1-f69.google.com with SMTP id v22so4456165ion.2 for ; Tue, 14 May 2019 04:49:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:date:from:to:cc:subject :message-id:references:mime-version:content-disposition:in-reply-to :user-agent; bh=3byTOZ1Myj651NO5kaGAKud48ExIes5ZKoTARDnqAyo=; b=oVeBNj3FbjWAZh+vMRQgcHraUnhIVQEDxxjMbOOLuKozntS7OCbFM9uT5371bBqMIH OPrv92uOdKSN/wJWQ5RVgQOgf06OKqjjmVwgAHmAOUQrUpL0VV7GATUx5mUM9A0USgSj xTvGxB+Y/2khZMPhRpjdKndNbaQ8/V/sIq6WuM/EKC8jai3XJJ8y1p7bM9lA+w8HcNLV GJGyrToT12rOSb5cFK03W1I4zRA/aXB1+b+Yo8Hs/TO06573K6u8NosVjBxP973QypTG s61kaKjmdXZNUtAMCQAeQWN0ry9MZJbN9PG5e/Ohr4qYpo3umJQQVVLCS7nyJ8e3F2kE UtVQ== X-Gm-Message-State: APjAAAX0+vj4Y9j6RZ6sPVxlBDHalMLKqk0nIqDtcDv58vY+/JdJOfHa xd1aL1KvCdQDc1qran/rXhe1i17DS5CB6PaTwTGi+6IuwwOukke3v5CGEW1FzJttJraQBsSHCly rgGqk/bVivW/0W8YsN+NlHvpGkqZwMm4CGw9v7lMrmw9SVqoCzV5ch+pHc/Lj7ahzUA== X-Received: by 2002:a6b:3ac3:: with SMTP id h186mr19443866ioa.63.1557834569612; Tue, 14 May 2019 04:49:29 -0700 (PDT) X-Google-Smtp-Source: APXvYqxbUWcy2W6ndOQzkF41kOeafqwS+IhsSkce+EMtZm7EZV9iBnAg/jG6s69XHiyC6EB2D4V/ X-Received: by 2002:a6b:3ac3:: with SMTP id h186mr19443831ioa.63.1557834569014; Tue, 14 May 2019 04:49:29 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1557834569; cv=none; d=google.com; s=arc-20160816; b=PvIAeFMXY5QD0XKeRwqXxznXAvo7dOxfKfXIOeJbMVyXxp7QSleHjLCI6Mnh1P+Ghn 1vatbQiHnrrbWvWAeze13+OiWmODK7eix2GejvHsmOQ/VPrIgazbA+3i+ISSA3G5h0m2 quy2Ctj8ZodyNvN0WdcTz9old5c6hrChPYb8LKq6S33NaQ4cBwwoiVgzmf91LYYJoZh0 EUcI79h1gNr0w97375fDkGqzZxUgEbuG0No/eHTlA5hUM2gIsNiUFvywaJ1hBA6BDAtV WDUulzKgqbX0WGdpGzv8BSeYeTAea5OLWIwMJ0Y01fc6itX851u/39TjzFkYjFiDKPBg jh7A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:dkim-signature; bh=3byTOZ1Myj651NO5kaGAKud48ExIes5ZKoTARDnqAyo=; b=txo94UhF8a1Uwpk3WTM4QCAnhpBnLQQMFyjbEMiYkGv+/SqAxeI3WF+Vn6/Ef06Lpf bFD57GiRUsLC0sAmk/a3iUYuH2dvqi82U8ugERKWs+iYpHW0sbWMlAxHQsKOeV6QauPO yedYbHVAOXPhJ3vjHqhGsJQl/8Jb+cthA+LIEc9Mpb/HDxgSbGmXGNsZ2z42wNOQfvrh fRAQnNIajlygvL2SOGqXvnMfd6zQjMbPy3xwO/IoRK93Q7rQNGYCAz8zeQ8NRmXL0Fp5 TwlnjNyu3rBteVhQy8Y4SrNxQAqTYu5VfIc8xGMohBfXy6OACZKkDG874YRpJM/Y9G3w Rztg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=merlin.20170209 header.b=TIFvPOXm; spf=pass (google.com: best guess record for domain of peterz@infradead.org designates 2001:8b0:10b:1231::1 as permitted sender) smtp.mailfrom=peterz@infradead.org Received: from merlin.infradead.org (merlin.infradead.org. [2001:8b0:10b:1231::1]) by mx.google.com with ESMTPS id 131si1322775itu.86.2019.05.14.04.49.26 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 14 May 2019 04:49:26 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of peterz@infradead.org designates 2001:8b0:10b:1231::1 as permitted sender) client-ip=2001:8b0:10b:1231::1; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=merlin.20170209 header.b=TIFvPOXm; spf=pass (google.com: best guess record for domain of peterz@infradead.org designates 2001:8b0:10b:1231::1 as permitted sender) smtp.mailfrom=peterz@infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=3byTOZ1Myj651NO5kaGAKud48ExIes5ZKoTARDnqAyo=; b=TIFvPOXmwezpA+bbGIElqbOPS 66JUG+655NExwAETL/RzqvHaEYb3sfEKCH39v0eO2yBmUTwYhhKH/0qL2WXRI5bXdAScd2g51vxcW j+x5oGqRAo10u1XTDs7HX1CnF5hZQV5X1VTev28CWBcT9QTCeaOuYHYwKqr3HKXig1DGDS6VFgy42 RH/v87y5MT3GWzAE7LaMPmD9eIFEkoMxeWIxz42MzdhwF9Yssn9pmMDRWrYEdskVe+PLq6DpHyUHV e4J0yibV60gN14RFX4NVqZp2TchwE2LNQZo3HGwTZbX7QiOEstYFh4hSbDe1/RAkI+LDyDilLes/f YS2aaM9pQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hQVvs-0007hN-GB; Tue, 14 May 2019 11:49:20 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 441122029F877; Tue, 14 May 2019 13:49:19 +0200 (CEST) Date: Tue, 14 May 2019 13:49:19 +0200 From: Peter Zijlstra To: Nadav Amit Cc: Jan Stancek , Yang Shi , Will Deacon , "minchan@kernel.org" , "mgorman@suse.de" , "stable@vger.kernel.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [v2 PATCH] mm: mmu_gather: remove __tlb_reset_range() for force flush Message-ID: <20190514114919.GO2589@hirez.programming.kicks-ass.net> References: <45c6096e-c3e0-4058-8669-75fbba415e07@email.android.com> <914836977.22577826.1557818139522.JavaMail.zimbra@redhat.com> <9E536319-815D-4425-B4B6-8786D415442C@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9E536319-815D-4425-B4B6-8786D415442C@vmware.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, May 14, 2019 at 07:21:33AM +0000, Nadav Amit wrote: > > On May 14, 2019, at 12:15 AM, Jan Stancek wrote: > > Replacing fullmm with need_flush_all, brings the problem back / reproducer hangs. > > Maybe setting need_flush_all does not have the right effect, but setting > fullmm and then calling __tlb_reset_range() when the PTEs were already > zapped seems strange. > > fullmm is described as: > > /* > * we are in the middle of an operation to clear > * a full mm and can make some optimizations > */ > > And this not the case. Correct; starting with fullmm would be wrong. For instance tlb_start_vma() would do the wrong thing because it assumes the whole mm is going away. But we're at tlb_finish_mmu() time and there the difference doesn't matter anymore. But yes, that's a wee abuse.