From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1F606410D26 for ; Mon, 2 Mar 2026 15:36:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772465812; cv=none; b=pEJFA0oo+EOT4OxFj1zzbEUkl2BwjSd8S5DLC24E/JS6dbGnsfWwr1Q8zwzWcvKcokRY1yNi3LenvtIc3BS62x/8hBMvzoJYyv/t8eU/BqU8f1zEWJ3UxlEBirhePX00ndHGg00871GNz7uVJn0WOsZLY1QMrDiWtZdb+MuzreI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772465812; c=relaxed/simple; bh=9oBA/2HWEPQ4Pcn2lNxOtCWpLciqSBzhtAatzajFUvU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hySjb+abb7W62Z2STMCDmrw72fX/96lKLavFnCKYIIKb6jyN1TSMoHiP1gV5CvWXk7Xl0Q51jSiZGBNdnD0lvuq/JV29NZX9UB1eyQJFIpzPSoVnQyc4rSY2/C56xf5RS6KMRyCDhVdoEchDSVr9P4Z5IdTyjhXK7TupnS1uQuk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=f4+nonEc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="f4+nonEc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1565CC19423; Mon, 2 Mar 2026 15:36:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772465812; bh=9oBA/2HWEPQ4Pcn2lNxOtCWpLciqSBzhtAatzajFUvU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=f4+nonEcvflPxCbCVfZuhIasP43yQlqIp79hgdYqHMdvYouDwGbtcF06EUjEM5S01 V0rGv7TaM3M4wlnkdoVtmRVNh/6WB3ekv5qFtRs+EOIb6cw8QwXSwQ40eLN/aIZ1yW K7KKesFUpRGc3KiAa2GLm2HxmtzYmtGAeL9PEgPfJHb1RtWm2YAJ7v8RT1wHQEQCqc Eq0WRsSdi6yWeUUnjurAL6MtTjFDgdq5CPQlahvE5V7VjR0JKDPmYhciZQg86Onaoh PwThto3B0pBJnOqTMVQzwUsp9M1lz3zSgYvIGnx0DKiFj8RsMZTTjxgWUZ/Qqtthru BnPf0xgC1dMmg== Message-ID: <6206d021-e6c2-4899-b426-cacd71ebd5ef@kernel.org> Date: Mon, 2 Mar 2026 16:36:44 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC 00/19] mm: Add __GFP_UNMAPPED Content-Language: en-US To: Brendan Jackman , Borislav Petkov , Dave Hansen , Peter Zijlstra , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Wei Xu , Johannes Weiner , Zi Yan Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, rppt@kernel.org, Sumit Garg , derkling@google.com, reijiw@google.com, Will Deacon , rientjes@google.com, "Kalyazin, Nikita" , patrick.roy@linux.dev, "Itazuri, Takahiro" , Andy Lutomirski , David Kaplan , Thomas Gleixner , Yosry Ahmed References: <20260225-page_alloc-unmapped-v1-0-e8808a03cd66@google.com> From: "Vlastimil Babka (SUSE)" In-Reply-To: <20260225-page_alloc-unmapped-v1-0-e8808a03cd66@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/25/26 17:34, Brendan Jackman wrote: > .:: What? Why? > .:: Why [RFC]? > > I really wanted to stop sending RFC and start sending PATCHes but > getting this series out has taken months longer than I expected, so it's > time to get something on the list. The known issues here are: > > 1. __GFP_UNMAPPED isn't useful yet until guest_memfd unmapping support > [0] gets merged. > > 2. Apparently while implementing the mm-local region, I totally forgot > that KPTI existed on 32-bit systems. I expect the 0-day bot to fire a > failure on that patch. I don't think you mentioned (at least in the cover letter) the mm resistance to add new gfp flags due to number of them being uncomfortably close to 32 already. But I see you've put the new one behind a config. Together with point 2 I wonder if this is where we can start making some flags and associated functionality 64-bit only and change gfp_t to unsigned long?