From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 138F0C3601E for ; Sun, 13 Apr 2025 12:48:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 002062801C5; Sun, 13 Apr 2025 08:48:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EF3092801C3; Sun, 13 Apr 2025 08:48:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DE19F2801C5; Sun, 13 Apr 2025 08:48:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id C0D4F2801C3 for ; Sun, 13 Apr 2025 08:48:36 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 328B3809E8 for ; Sun, 13 Apr 2025 12:48:37 +0000 (UTC) X-FDA: 83328999474.24.3E0D46E Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf05.hostedemail.com (Postfix) with ESMTP id 05C09100007 for ; Sun, 13 Apr 2025 12:48:33 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=SGufiG16; spf=none (imf05.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1744548515; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=BYd9ghzIbvgBQxn74x2yQL2hqEOdpaPt3okp+tYy+YI=; b=EZH1L7JjuKrj/6IWe4PE0UvDP0E2hGzLQ9qfKhX349doQQboruC2ANIiQJqt9Msxi7In7O NwwLSlJzhZoSNpCo4kyGhFu7DOZ7Ch0ueAj+JaGrkp8+hBGot5CDXsXMcAm5XEUMBo2bIs 3Or4Dw3IA6GsXAk4yiwwoSpBlsHD3DA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1744548515; a=rsa-sha256; cv=none; b=uo9jsPp5deRRV7bVGMw7cYHIQGfWr1XOGQHY02to2GO69s5PxZWXOS4E1He2K9WGab5Y7E +RNdHdhxXiyRamnNVTKCghIfQ4J1dS/shXxu2PCAKegSy/1rFJAzvlpy5Ak9z916lcVd5J Gle8U6EZ7bqRNnRiaHdYMBPekcWKJdY= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=SGufiG16; spf=none (imf05.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=BYd9ghzIbvgBQxn74x2yQL2hqEOdpaPt3okp+tYy+YI=; b=SGufiG16PzYig2XsU0/e5Eg5VY Nrz1kUIZf1J4TK69G0cSJe88bZuAFUerzAYATIWklMfuyBy4evF9LW3qlxdb+o+zZCdfFGVTeniUK hl0Hi7DdUVsKYEAcu/47Gf1HK+3N4KGc5bvAmePpdih0gKpX9X4LwBR3g3vMsr//bmQUZVWp4g1pz GVWbgGoEAhrwg4HJCxlh+1lCzdaKxnHWVgkEdrDimsA9bryaMCCLZMixbN0PZeJ9YZo2gClBAUMAr 6xyHlkg+FWPhMKZ2mMr6rYCTze1Bijcfaf+c/87MnHxgKTJZbXC9SKGCNHaahwveAINGGXaUYaGcP dSH+632Q==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1u3wl8-00000006o5h-3PQP; Sun, 13 Apr 2025 12:48:26 +0000 Date: Sun, 13 Apr 2025 13:48:26 +0100 From: Matthew Wilcox To: Donet Tom Cc: Gregory Price , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, Huang Ying , Keith Busch , Feng Tang , Neha Gholkar Subject: Re: [RFC PATCH v4 0/6] Promotion of Unmapped Page Cache Folios. Message-ID: References: <20250411221111.493193-1-gourry@gourry.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 05C09100007 X-Stat-Signature: g5sitzy5wedb18ornpmittreryj8fbta X-HE-Tag: 1744548513-928544 X-HE-Meta: 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 0ZsfUgVY s74+8BHGeq6BCAhtQAA1fshLviJwi0JFguOfhUkVTHo3RygCx7HR1wN+6T+iuU/PvUOYVPwxEP6mthRFNgdHzl0cVCRbn1c6+GuNMA0ahZXdpNwpYxsSJ5gKJkjmbCNx8wk+4eKrY1/0pBw7vE66Vch+J/R6ReFCGHjjhBmiR1eaEmWdq6xPweQaTk00VKg0O34bYxi/FGLO8MKenl6ECw9anU445bgy+sPsSMA12avL9WVI= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sun, Apr 13, 2025 at 10:53:48AM +0530, Donet Tom wrote: > > On 4/12/25 5:19 AM, Matthew Wilcox wrote: > > On Fri, Apr 11, 2025 at 06:11:05PM -0400, Gregory Price wrote: > > > Unmapped page cache pages can be demoted to low-tier memory, but > > No. Page cache should never be demoted to low-tier memory. > > NACK this patchset. > > Hi Mathew, > > I have one doubt. Under memory pressure, page cache allocations can > fall back to lower-tier memory, right? So later, if those page cache pages > become hot, shouldn't we promote them? That shouldn't happen either. CXL should never be added to the page allocator. You guys are creating a lot of problems for yourselves, and I've been clear that I want no part of this. >