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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 5A126C021B8 for ; Wed, 26 Feb 2025 20:00:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=bmH1S/Rzq0FxLgrO/eJfpYA5Zf/HpcpQ6JQLKa/UX3k=; b=cY/3M5HerMg0ymMFkOmswPqxub bX3NU7L6HoVc0NGq7tpFMfD0n5EheoDAJvYazSEbebF1t/7kvzj+mtPeAAKT8FaarHJuawpNLtaC6 OHXyinkoFrSxAlHg6JWwYJwAxVurL7hWRDk/oLCFiWhYQ3ix6nOOGN9UHLCY9RnXxXjlLYaFvoKu3 X0gR8DPqK2tpB85CBuArpZ9f3xT0ysdYb3wCuMVyrd7s6NNVN2+4zQaMbCJB4t8UwCl5rBp9M2lDg GW98XCav4MnKcg/ttxU08/1E1pFaKn2k8HNR72JEUb7J41yaRKMbx5qJsDc0qXDhAOMky6SKCbLCF E/Zm3hnQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tnNaF-00000005Fke-3lAe; Wed, 26 Feb 2025 20:00:43 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tnNaE-00000005Fjr-0PxD for linux-nvme@lists.infradead.org; Wed, 26 Feb 2025 20:00:43 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id B70DE5C7421; Wed, 26 Feb 2025 20:00:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3280C4CED6; Wed, 26 Feb 2025 20:00:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740600041; bh=s8TR3mzU4dAMr2KyS/iGUHeMjkOW+Z7uBLL2Cfc8pv8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=H/8mBCQ41anFup23sLTi2aX6kI1lAvfNfisC4VpALVIUdEdyqz1s/RnGg2Gb0m8By BhGak0lQ6yLccO52xvYlgpkvy6j34JYqx8v9jKBln0uUPLVtau0fVmGKH1+IyfueLZ AAe3vmi3ajnzEMG/d4KcU3Ak7PISIxRRdA3j6TwLNiScj0GwrufM/EEsD8aPWdvAr9 hEz3nMXGnbf8se/MR/U3Gagjys9Hslf01IB5RmeRNZHK8/W/K+d9aSepbvAHjMFPgx XQhROwkwuHJFESs5lROHb58sICPYDdvLVuzdMUuDvoK6GTHCmKgb95mmvK6tdbIM0q IuD9DR2ZPeNhQ== Date: Wed, 26 Feb 2025 13:00:38 -0700 From: Keith Busch To: Jens Axboe Cc: Keith Busch , ming.lei@redhat.com, asml.silence@gmail.com, linux-block@vger.kernel.org, io-uring@vger.kernel.org, bernd@bsbernd.com, csander@purestorage.com, linux-nvme@lists.infradead.org Subject: Re: [PATCHv7 6/6] io_uring: cache nodes and mapped buffers Message-ID: References: <20250226182102.2631321-1-kbusch@meta.com> <20250226182102.2631321-7-kbusch@meta.com> <83b85824-ddef-475e-ba83-b311f1a7b98f@kernel.dk> <5f46cba6-0a11-457f-8591-732f709e7fea@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f46cba6-0a11-457f-8591-732f709e7fea@kernel.dk> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250226_120042_180742_76B6368D X-CRM114-Status: GOOD ( 12.29 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Feb 26, 2025 at 12:58:21PM -0700, Jens Axboe wrote: > On 2/26/25 12:43 PM, Jens Axboe wrote: > > Ignore this one, that was bogus. Trying to understand a crash in here. > > Just to wrap this up, it's the combining of table and cache that's the > issue. The table can get torn down and freed while nodes are still > alive - which is fine, but not with this change, as there's then no > way to sanely put the cached entry. Yes, the imu can outlive the table it came from, which means Pavel was right to suggest I not tied the cache to the table. Thanks for pointing this out.