From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 349295476EE for ; Thu, 15 Oct 2026 16:28:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792081698; cv=none; b=ZfiWCHmT48w+RUD79cx7y2skUoGGFuDDGpqWHQ/S6wyv+Woed5eAlXVHbpYC7zHFTKcOiYS9aV1nm+K0UWzrCJFfoy+ib8Zw/Dzmf7HtCdqqzWPKlKOyltqrT1CcWSy6IGMVmkFYZFe9p53VdvqReGe10M2ct7e3dxXEnATGb14= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792081698; c=relaxed/simple; bh=XLnWwWNMPSm6y57bf4F4xUjaAeFj35H0VYjcsc11Jog=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UXc97WT4+mD/jBcOq5seNRHiZ48M0N5o+P7XROfwXOwj3LdRpY1UF2BuM50CfdTuWE+GfOOUNSle0IBb3y7BzT81w7R39QL9y/rJ/a7CFHfkrTGRFhmsRcRhbr/0ttsYeHV/n/l0AQb7cnnKrmAHjmQst0bDnQfj74RwaNblZQQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XoDoNgJY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XoDoNgJY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D6661F000C4; Thu, 15 Oct 2026 16:28:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792081686; bh=XLnWwWNMPSm6y57bf4F4xUjaAeFj35H0VYjcsc11Jog=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=XoDoNgJYJMqr9vyGRiW3ypkgKBopgiUuSRDg6wNPKmdgpfrW11xHPPaLdEyhNhDW2 YUWvLh5ZV6hNwVJOcu38x0CgKFxpxvreAHI/1jqpxTxcGmC5sFaPZJYCcY0CmpkzNb JWi4NEC9MyrEPpInNFS8cqXGiLyHLtLA6k7Phsjfs8vDXr+ddqa90jgGpwSoINykgE xJo88GhhHwORpaTZvHUTgfYQIK8eg6DnI28n27yzbJ468Gs3XIn2Nkc4xJeM3R3GXg zLKQFLzJJxiYcXKBjL7TsHfAYCFyKYddxGlaniCrm3xPQJye5eaISd4aI8RSy6mnXN AHqD8M4tv4JVg== Date: Thu, 15 Oct 2026 17:28:00 +0100 From: "Lorenzo Stoakes (ARM)" To: Daehyeon Ko <4ncienth@gmail.com> Cc: Andrew Morton , Suren Baghdasaryan , "Liam R . Howlett" , David Hildenbrand , Vlastimil Babka , Mike Rapoport , Jann Horn , Michal Hocko , Shakeel Butt , Pedro Falcato , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: prevent VMA generation reuse from skipping readers Message-ID: References: <20261015143735.1630957-1-4ncienth@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261015143735.1630957-1-4ncienth@gmail.com> NAK. You're making VMAs a cache line bigger. Since this is the second time you've done this - stop sending patches to mm, we don't want your AI slop, thanks. (In future you'll likely be ignored.) On Thu, Oct 15, 2026 at 11:37:35PM +0900, Daehyeon Ko wrote: > Both values are 32-bit. After 2^31 complete mmap write-lock acquisitions, > an old VMA stamp can alias the live odd generation. vma_start_write() then > returns without waiting for an existing reader. This is really unclear, I guess, as before, a member of the core team (likely me) will assess this to see if there's anything actually valid here. -- Cheers, Lorenzo