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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2EBEDC54798 for ; Thu, 29 Feb 2024 19:38:02 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rfmDn-0002Kw-3B; Thu, 29 Feb 2024 14:37:35 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rfmDg-0002Kc-MR for qemu-devel@nongnu.org; Thu, 29 Feb 2024 14:37:30 -0500 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rfmDe-0004GC-0a for qemu-devel@nongnu.org; Thu, 29 Feb 2024 14:37:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=8uNmGuKJqG0ZLwvelugqTwty9eAp95ps/IXd1VUbjRE=; b=LfHiOuS377ugSXr21HSPLjoGds rRHRotHB6Z2K+UknnXnK+QSxqb+aTii8MgmSzXW1sRNBptAvRcgkCTNz6J+ZbnsCs2gOL69/7CQwh HbpeH4t5yDhGvqmnlTjCTBFsDyp9akGVrkIGj6y3BedRK3Vygt5msrjSPEYVN6VtIWpZchOzssQ/V WR1aOx0+dyY/SjdSpU3JUwI4U2i/3gjC67frvRbY1ZlyHhnna281LjFJ9s/SzckoOzX+rHWRnRD4q DbfpzdwBNaELy6OKw8HL8OqWb7AQNPVnsIkMg3yiwsLXR6E9Xx/G6dwkxCxOWFcKJ/oDRVozID8PI 7uk/dp4Q==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1rfmDP-00000008qqb-3bC7; Thu, 29 Feb 2024 19:37:11 +0000 Date: Thu, 29 Feb 2024 19:37:11 +0000 From: Matthew Wilcox To: Greg Edwards Cc: Jens Axboe , Andrew Morton , "Kirill A . Shutemov" , Hugh Dickins , linux-mm@kvack.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, qemu-devel@nongnu.org Subject: Re: [PATCH] block: Remove special-casing of compound pages Message-ID: References: <20230814144100.596749-1-willy@infradead.org> <170198306635.1954272.10907610290128291539.b4-ty@kernel.dk> <20240229182513.GA17355@bobdog.home.arpa> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240229182513.GA17355@bobdog.home.arpa> Received-SPF: none client-ip=2001:8b0:10b:1236::1; envelope-from=willy@infradead.org; helo=casper.infradead.org X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Feb 29, 2024 at 11:25:13AM -0700, Greg Edwards wrote: > > [1/1] block: Remove special-casing of compound pages > > commit: 1b151e2435fc3a9b10c8946c6aebe9f3e1938c55 > > This commit results in a change of behavior for QEMU VMs backed by hugepages > that open their VM disk image file with O_DIRECT (QEMU cache=none or > cache.direct=on options). When the VM shuts down and the QEMU process exits, > one or two hugepages may fail to free correctly. It appears to be a race, as > it doesn't happen every time. Hi Greg, By sheer coincidence the very next email after this one was: https://lore.kernel.org/linux-mm/86e592a9-98d4-4cff-a646-0c0084328356@cybernetics.com/T/#u Can you try Tony's patch and see if it fixes your problem? I haven't even begun to analyse either your email or his patch, but there's a strong likelihood that they're the same thing.