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 5596935A387 for ; Mon, 11 May 2026 18:02:00 +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=1778522520; cv=none; b=eJCVcsskng6hDuUyLB1ALoWicncSFnuFwRHd+QCtx2loR+Ahmpo4wrmtcIzrn4BCxu6v/S/RIu9OXCyJ8HmIxwTRCpEDD6ASftomY6F5IpRJrcqQyjMTf3rlETdlKtNrfKFAKsjXaHWKbw8ipyl58Jkf/uASyZEf8iO77LRl/go= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778522520; c=relaxed/simple; bh=T/YZyuolzIqH4cmCWQ24sR5GevwICNeNnPOgTZpXM0Q=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=K5DKSqlF2z1dKNqpuhuzCHbryCDaLYsRGpat5RjeLrw6cK16gC20BAr40iur5SmID021O9pgp87VniRwvCTjbUd3bQ8P6HvbqiktIW7DhYFIifp7Ffpf1ZdM7rT8ImoKmikP1WnVjrYyjN0/OIjtPzHp8xHrZQsoS4TM87DUhUg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VQvIVbRx; 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="VQvIVbRx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CB9BC2BCB0; Mon, 11 May 2026 18:01:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778522519; bh=T/YZyuolzIqH4cmCWQ24sR5GevwICNeNnPOgTZpXM0Q=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=VQvIVbRxmF2YDwIDqPeXTx24ipPzfJIMeB0O5hBUJ8mvTxPTdODBPk/0Eitv91Ttk /KCDosScXsifvMGEzcKCM36lu8iDmK1e1v4TcTnkVXUMJIW+rOByA7cfnrw9PrkN2B zNYA2+lU2qztTWKvhVx5iZabjFRof+la4PJEOwXhazDiiZSUAWK08iMZNX81RTyo5n itietPph40OPqjRmMOCvHOoLTsLlJ+d7Q4i7yBGPBvS/Cng2RYVyNENgK4O7RBPP4m 2iQ+G9+Oozq0ISVVKnQ8cxnf6JTrdTr62WA7U8TM/qtpA4dwdbv++0nEQrx1UAcZwt SCtXzNq2Qq83A== Message-ID: <2efea0a2-0c3a-40b5-9f76-dc0613725b0b@kernel.org> Date: Mon, 11 May 2026 20:01:53 +0200 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 v2 12/22] mm: add definitions for allocating unmapped pages Content-Language: en-US To: Brendan Jackman , Borislav Petkov , Dave Hansen , Peter Zijlstra , Andrew Morton , David Hildenbrand , Wei Xu , Johannes Weiner , Zi Yan , Lorenzo Stoakes 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, patrick.roy@linux.dev, "Itazuri, Takahiro" , Andy Lutomirski , David Kaplan , Thomas Gleixner , Yosry Ahmed References: <20260320-page_alloc-unmapped-v2-0-28bf1bd54f41@google.com> <20260320-page_alloc-unmapped-v2-12-28bf1bd54f41@google.com> From: "Vlastimil Babka (SUSE)" In-Reply-To: <20260320-page_alloc-unmapped-v2-12-28bf1bd54f41@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/20/26 19:23, Brendan Jackman wrote: > Create __GFP_UNMAPPED, which requests pages that are not present in the > direct map. Since this feature has a cost (e.g. more freelists), it's > behind a kconfig. Unlike other conditionally-defined GFP flags, it > doesn't fall back to being 0. This prevents building code that uses > __GFP_UNMAPPED but doesn't depend on the necessary kconfig, since that > would lead to invisible security issues. > > Create a freetype flag to record that pages on the freelists with this > flag are unmapped. This is currently only needed for MIGRATE_UNMOVABLE > pages, so the freetype encoding remains trivial. > > Also create the corresponding pageblock flag to record the same thing. > > To keep patches from being too overwhelming, the actual implementation > is added separately, this is just types, Kconfig boilerplate, etc. > > Signed-off-by: Brendan Jackman Aside from the gfp vs internal flag decision, seems fine. Acked-by: Vlastimil Babka (SUSE)