From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 C67BA3126B6 for ; Wed, 22 Oct 2025 09:10:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761124204; cv=none; b=i1HJEUgxmIP5SWPoaeWRDn17/WepyLbGVDy7hrJS5TlQHvusLTyugzw5BWl4MC+87iSm5gh2xN0oTBU2gMMKGis5VmcH3bvegFD7mNwssqJogJuPcbjNQRw7moDVJIwWJqOzY5IIDDivbe9pAWxa5CHC7neB8mhWAK3jkuCtKGk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761124204; c=relaxed/simple; bh=Xwh3l3BPA4ZgKUZ7PgwsvS6awxKnTMHACbPXbU0DDZU=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=h1vfG3zpOy4Q8tnrS9tGhC2WMSYh01+2EYdAkEuoIorq/d1yxh8KXNx7hd3dNWK9lnHqU6JffDDhyfHnN042s5vuozpmmBHxbjLflUEKJBMdFyBoQ+Eomhv3Rk3nozkXh+SDDXaicY6W3UofSR4bJmL8il3Nt/LcMYzUR6nM9Tk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4cs3HP4d4Dz6K6HJ; Wed, 22 Oct 2025 17:08:33 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 84AB21400C8; Wed, 22 Oct 2025 17:09:57 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 22 Oct 2025 10:09:56 +0100 Date: Wed, 22 Oct 2025 10:09:50 +0100 From: Jonathan Cameron To: Gregory Price , CC: Yiannis Nikolakopoulos , Wei Xu , David Rientjes , Matthew Wilcox , Bharata B Rao , , , , , , , , , , , , , , , , , , , , , , , , Adam Manzanares Subject: Re: [RFC PATCH v2 0/8] mm: Hot page tracking and promotion infrastructure Message-ID: <20251022100950.00002785@huawei.com> In-Reply-To: References: <20250925182308.00001be4@huawei.com> <20251017153613.00004940@huawei.com> <20251020150526.000078b6@huawei.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) 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-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml100012.china.huawei.com (7.191.174.184) To dubpeml100005.china.huawei.com (7.214.146.113) On Tue, 21 Oct 2025 14:57:26 -0400 Gregory Price wrote: > On Tue, Oct 21, 2025 at 02:52:40PM -0400, Gregory Price wrote: > > I would prefer the former, since this is already what's done for > > hostbridge interleave vs non-interleave setups, where the host may > > expose multiple CFMW for the same devices depending on how the OS. > > bah, got distracted > > "Depending on how the OS may choose to configure things at some unknown > point in the future" My gut feeling is the need to do dynamic NUMA nodes will not be driven but this but more by large scale fabrics (if that ever happens) and trade offs of host PA space vs QoS in the hardware. Those trade offs might put memory with very different performance characteristics behind one window. Maybe it'll become a thing that can be used for compression. Otherwise compression from host hardware point of view might be like the question of share or separate fixed memory windows for persistent / volatile. Ideally they'd be separate but if Host PA space is limited, someone might build a system where a single fixed memory window is used to support both. Possible virtualization of some of this stuff will make it more complex again. Any crazy mess can share a fake fixed memory window as the QoS is all behind some page tables. Meh. Let's suggest people burn host PA space for now. If anyone hits that limit they can solve it (crosses fingers it's not my lot :) Jonathan > > > ~Gregory