From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from va-1-115.ptr.blmpb.com (va-1-115.ptr.blmpb.com [209.127.230.115]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8824344F564 for ; Wed, 30 Sep 2026 09:00:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.127.230.115 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790758831; cv=none; b=BY9gzouEJN9RoiWraNmwIaENDnWCNP3Ebz0uS7Klo0k5AsKNeLe9dCCRiOjR0QcS2h7qqQur28xCaO41KoK3LdS+TP5HZbQpvDP3movNgDL3/5cGDPADRkoTppFGNmYnQXQWc+up7pmyxFRyj0sVUhnFPfS8l5NdJyEeO4ktI4s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790758831; c=relaxed/simple; bh=Vbt5iyPLRXtEJgyVkzGCbXczZDhTv0UsZ2K6hMdH7UQ=; h=Date:From:Mime-Version:References:In-Reply-To:To:Subject: Content-Type:Cc:Message-Id; b=Qm0af7COslDI7k46C6qSXJJg/VB0wWRg2HLQh1MQPd+aDf96pAXh+pgITo8ZQGgH/Sqy1AM4KUt7Pnpw9SU0AIz0my8cykVjetO6u1mCwYwy3JKLAPDl+sKQXV3Xv7j28kyIAdZAezqc/RhQibb6xrtKoywEP0JrPazuKHx7t80= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=G67RfIt5; arc=none smtp.client-ip=209.127.230.115 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="G67RfIt5" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=2212171451; d=bytedance.com; t=1790758825; h=from:subject: mime-version:from:date:message-id:subject:to:cc:reply-to:content-type: mime-version:in-reply-to:message-id; bh=CyczEz5gT341e5VUYWKWi3gWeXf1xphfZZ7IhgAwPn0=; b=G67RfIt5uJ2Cmbppq6XHyrZv0cuB/SVJ0F8IxSPmIOzkofMVEeEfrPS3SwonFLIrzJsQel x7sJxk7bLPPbZAJnlm+ZR11vLXeWLhhTT3IkGLuCnUNpPTtn5959UrtGuxXqb3Gu3eRnOC wvvr1F/TlI1buwsrvOW9qBrHY8RuWakQgF82uSqnXbEPOHHc4lBFG9v/vOLPVHR2YbzI1x Vmr5Iy6qgn7YgsPrOqsNAB2W0bUFvrZ/bq3aZ5d9jscPuU2+YifNEk2sYJg+T8A8WEJd/z sv06Brjzq1yVIzHVsGyJa+pauMlGo2DiwEJU6VWJjRGQUrDyclTvLXhRC/odTA== Date: Wed, 30 Sep 2026 16:59:50 +0800 X-Original-From: Li Zhe From: "Li Zhe" X-Lms-Return-Path: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260930072617.64665-1-lizhe.67@bytedance.com> In-Reply-To: To: "Gregory Price" Subject: Re: [PATCH] mm/numa_balancing: allow migrate on protnone reference with MPOL_WEIGHTED_INTERLEAVE policy Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 User-Agent: Mozilla Thunderbird Cc: , , , , , , , , , , , , , , Message-Id: <7df34f77-2c52-47a3-a495-d782009ab543@bytedance.com> On 9/30/26 4:43 PM, Gregory Price wrote: > On Wed, Sep 30, 2026 at 03:26:17PM +0800, Li Zhe wrote: >> Allow MPOL_F_NUMA_BALANCING for MPOL_WEIGHTED_INTERLEAVE. As with >> MPOL_BIND and MPOL_PREFERRED_MANY, keep migration constrained by the >> policy nodemask: if the CPU's node is outside the nodemask, do not >> migrate the folio there. >> > Why for WEIGHTED_INTERLEAVE and not INTERLEAVE as well? Thanks for pointing this out. I focused on MPOL_WEIGHTED_INTERLEAVE in v1 because the motivating use case is to seed memory across tiers with a configurable ratio at allocation time, and then let NUMA balancing/memory tiering adjust the placement based on access patterns. With equal weights, MPOL_WEIGHTED_INTERLEAVE can also cover the regular interleave allocation pattern. That said, I agree that MPOL_INTERLEAVE can be handled consistently as well. Since this is still an explicit opt-in via MPOL_F_NUMA_BALANCING, unless others see a reason to keep MPOL_INTERLEAVE out, I will extend this in v2 to cover both MPOL_INTERLEAVE and MPOL_WEIGHTED_INTERLEAVE with the same nodemask constraint. Thanks, Zhe > > Otherwise this seems reasonable. > > ~Gregory