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 1CE1FC369A2 for ; Sat, 12 Apr 2025 00:36:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BE3E8680036; Fri, 11 Apr 2025 20:36:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B9259680024; Fri, 11 Apr 2025 20:36:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A8099680036; Fri, 11 Apr 2025 20:36:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8B495680024 for ; Fri, 11 Apr 2025 20:36:05 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 881051409FB for ; Sat, 12 Apr 2025 00:36:05 +0000 (UTC) X-FDA: 83323524690.12.B7D9CFC Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf15.hostedemail.com (Postfix) with ESMTP id AE256A0005 for ; Sat, 12 Apr 2025 00:36:03 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=Cp1WlN4I; spf=none (imf15.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=1744418164; 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=jLcp1f7cOvcMEIXPWzRzzeb25u2ahPnJh9qFDKIguvo=; b=pScPWeoPlLEZRLXFBB8Ofue5FnwpjxMJFgAef9Z/ggkMZENYuVIVrDNuFa20nv2VQ+m4oB D8fXYbuG0ySsclj72Oxm55So9Ki7rUzlW/8O2a6VupDiEp6KT9w7awA3NJe768oogVoCjG S0JaiPEFdttVyE/VBxPR3GwuE4LpCys= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1744418164; a=rsa-sha256; cv=none; b=2wn4csVurmjUazc3nVjZxxsM62u4mJjSfjotLcehf63Fuk237crJ+PzqHodF+FOIzReBmo I+GkU9Kg17mls8Kyvy/r46Z0tULRvwcMjQfbt0jAccgMHdhVdH6FFfkV6a3GYg1t3SbcPT ZyGNXDbd5R0dgE/H2cpWQngfStiz4F0= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=Cp1WlN4I; spf=none (imf15.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=jLcp1f7cOvcMEIXPWzRzzeb25u2ahPnJh9qFDKIguvo=; b=Cp1WlN4ISq7YsoEqphP6c04d4C 15BcntTpC5JcklAwoYa9UcSYoepyO8BfZpy1wE+0g8AWtNz6h6OSxPDv/o3EPzTyQvNZ/WQHfaDhv 7r3rjuFNTF08ZLTqTYy/a+JCI5l7iZCIUmB4xWCT0+3qH2dBdPlibHfpFg0QLnW/ho4FJKqhnGeyI x6z0qfH9/FmnXRRGMyJ8cZMdnxKNuEekEodSvO1ZyG/aluAJSQK5ZPZ66d7dkXtWooe2PFuFRe8mQ 3IOJl9uDfZ+oH1GxJvBDurKZSZe5GVvmXvPoX1eejHdAMmY0oe37gbbwpadx/mBXfdPGK76PDnGRd Ak0iZi+Q==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1u3Oqi-000000052MS-25TP; Sat, 12 Apr 2025 00:35:56 +0000 Date: Sat, 12 Apr 2025 01:35:56 +0100 From: Matthew Wilcox To: Gregory Price Cc: 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, donettom@linux.ibm.com, 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-Stat-Signature: opd9oupxyqfmheu195dw5eajz78qxtnk X-Rspam-User: X-Rspamd-Queue-Id: AE256A0005 X-Rspamd-Server: rspam08 X-HE-Tag: 1744418163-756583 X-HE-Meta: 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 Ky5yJQ+U rXk9Hk2aIF100sYiU+vvu6dorPn5iYkKJ8yQC96IKr+wj70b6uRsHM38sKZ0Vv+JF5Fi10AigrhLLw3fqPIJLb4/qUUJNqCpycq0RvihXP7J4+2HhoN55zAOp+HvQp5O7dM1S5tkv4uID4hMvKx8P09uJ6c+TsDPwNatJe4qMtXejGxSWE+1w8sro14pQnh0AagO21/7I/8a5dAfniTMqYQKZKp3vJzD+aGXQGURTKjCpXQ8= 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 Fri, Apr 11, 2025 at 08:09:55PM -0400, Gregory Price wrote: > On Sat, Apr 12, 2025 at 12:49:18AM +0100, 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. > > This wasn't a statement of approval page cache being on lower tiers, > it's a statement of fact. Enabling demotion causes this issue. Then that's the bug that needs to be fixed. Not adding 200+ lines of code to recover from a situation that should never happen.