From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793035586; b=xdMbxwyr7uACd7fWAvShbkINYYixrenBwHUS6oJk35JWsZSKi4WVB2j3bKtZgbftmvDE J0O5R2Rm0DF5gKA54Q9C/xqsnMhu9+YvecrDUFuo6iOzKzctTzBxACG6xPylvhNL4j2+V 1g+3FnPtREOL4n4aH+zRR0UQ6AZ4IZWLH3tqVe25Hhb7n0PkPnx9DkwkN8+ToD3hF3cN6 5uahdnlCPBfkvON0c07rOyC039qAuV/lBQMeWUebLgLaJT0akjJjzcsE5HNLPF27cKRgI 9h2TXsQOCRF1ZwS0t2oBzlha8QsRe3qe9kjWI/cSFvAl56FljpB69wix2wvkq/bxDKw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793035586; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=v0WoLkQVcDbSGumghdYohAdB7aedqeHVhzhgY1ziDNE=; b=WgrZNwBtQwWwdgAogVT1FFqi6KdesdUxYfWbSA9Re6RZCimzN0O7vnvu+tnicqeYZ2bL O3lOEAziQgh6/IiVtOZsDzOVarYDP8NdVuf9iBj/CfqeHbPsslHJ3SjeInjJGHegZ593E w4EeEg90Sg41D/fmHhBbJy+ao4SNwk9UKJz28+/d6n8tGwWr7Hj4ygjU+k5vgF95DK1mz 063GTeVkzEOr+F1GRa/TXCp6OKLiIAo6KZvsUWAeoiIU8hHACfdL2G3tqahto9URdhv11 J31BPq25q7Pbi/AxkLKku/iaurdR2kkHzumh/fOuDYKTHwSMPFKzXTpOUdhyBDNkWOA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="UJjjE+w/"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3D98B606A321; Mon, 26 Oct 2026 17:26:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=UJjjE+w/ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 715BA1F031E0; Mon, 26 Oct 2026 17:26:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793035586; bh=v0WoLkQVcDbSGumghdYohAdB7aedqeHVhzhgY1ziDNE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=UJjjE+w/YXLWI0UQBaYCVSGw3pw3SwVACw6Xl+vENBzMgcxNnqssVXl0whwdZzcFb aC6PVbgiG6rlNIXffQ7/CSshM+uJ8wofvwoA1WQbx2twWv05gNKRg4zbsOownetahZ gFqHdVAHaa3wyS6p0m6KygE/nIb9evXkgph0RHfLnSfIOwZgiTL9LSQdNGAF+1RSMl IFjgRMmUPEb15cci+VVrTv/2t4ClbdIC5xeM+YipLCAN52E/YyYnQnty8bueg8Kjk8 V9EiWb/e5kJwlanYEdX4xzdWyceuMjAb6jV89DNZrgaxizTDfn/4TY6Ut2Hu0slW30 6xFiw0AichPIA== Date: Mon, 26 Oct 2026 17:26:20 +0000 From: "Lorenzo Stoakes (ARM)" To: "David Hildenbrand (Arm)" Cc: Suren Baghdasaryan , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , Shakeel Butt , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org Subject: Re: [PATCH] fs/proc/task_mmu: fix missed VMAs when reading /proc/PID/maps and friends Message-ID: References: <20261025-per_vma_maps-v1-1-c4eec45b9387@kernel.org> <8c5a8fb7-233e-4433-af45-b67cb2528b60@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8c5a8fb7-233e-4433-af45-b67cb2528b60@kernel.org> On Mon, Oct 26, 2026 at 06:19:18PM +0100, David Hildenbrand (Arm) wrote: > >> + /* > >> + * No lock was held since the last call, so the iterator's cached range > >> + * may no longer be valid. Always restart by address. > >> + * > >> + * The vma_range_is_empty() checks below avoid unnecessary mmap_lock > >> + * fallbacks. > >> + */ > >> + vma_iter_set(vmi, from_addr); > > > > This is clearly simpler but this unconditional vmi reset is not ideal. > > Yes, exactly how I ended up where we am right now. > > I pref my current fix as something to backport that avoids performance changes. > > If you two disagree, please take it over and drag it over the finishing line in > a timely manner. > > I wasted enough of my weekend with this over-enginered piece of software. (had > to change one word before sending, can you guess which :P ) No problem, will take over. -- Cheers, Lorenzo