From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 CBA04442FB3; Thu, 13 Aug 2026 08:28:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786609724; cv=none; b=NsS755BTQcLJzGEfNxQzUDydW4JCz0hjdhBgoPTlfgUCTBucmv5vSH1jiYzkqZSNX1jIjlM1xLot+8t91vCKwxPs32HqcfVDwgzGyjoYmjRnnE+FpzeashEFEq0NRam275DHqg7zWqV+ZVIaVmaoedXm+AZ/KjAfifdWbMcxB78= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786609724; c=relaxed/simple; bh=ksjfrsjrqio69wjpS7hlRyuiSuUBYHv0ukkeBype3Rw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=j0vDazsfPGW/KVFOf18Or6+e80fnI5tCfmzY3XSgbr2UQ4qvqka+4NQXwOHcIBhW9hns1KwgN30lpifiNcv+upLi9NbaHq9UEPE9SXtRJwJjG+tBp0CePEXAAB6yVhp9BWNxMt/n9/Em2klgn5J9fNioLcR2uuo8paLMAkgxRPc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bMs9RZNC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bMs9RZNC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B34981F000E9; Thu, 13 Aug 2026 08:28:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786609722; bh=uIuTH63rkuXcFm6et2f7wSWkhuN5eE2vt+vtDQrJL4s=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=bMs9RZNCuFCGpxMnuN/GlcJjkXynXrV0LclIUQD6JvPK5QrSyTBQJTqUF7+TVW6FO 1K6z3hMAOA099qVd5GR6tSZjx8FS/X+8lBZ0/AKAYK7ucrziX4+PuEoE80THntxuv/ TWHocyxmoUw4hOODVAZGbvUGeKk/JYZgzhdD45h8/FyxUgYRW7m/BKkgL54bPfKj6u EfPE8kCQlMS8f7unbRmZMB3/eGv1hSRzv8p2/iyQRpRNe+A6xO/ZBBBYt2GyLBO/dI GaO558pnhFY4zgrgplFktxr/jxQNTn7H5CDgLwqFJuRiUyz6PEVLR6PTunViHie0Jm KQGFkf8cvD1DA== Date: Thu, 13 Aug 2026 09:28:19 +0100 From: "Lorenzo Stoakes (ARM)" To: Gregory Price Cc: SJ Park , linux-mm@kvack.org, damon@lists.linux.dev, linux-kernel@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, david@kernel.org, ziy@nvidia.com, baolin.wang@linux.alibaba.com, liam@infradead.org, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, usama.arif@linux.dev, vbabka@kernel.org, jannh@google.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, ying.huang@linux.alibaba.com, apopple@nvidia.com Subject: Re: [PATCH 1/4] mm/damon: defensively skip zone device folios in damon_get_folio() Message-ID: References: <20260807000938.79851-1-sj@kernel.org> 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-Disposition: inline In-Reply-To: On Wed, Aug 12, 2026 at 10:26:08PM -0400, Gregory Price wrote: > On Thu, Aug 06, 2026 at 05:09:37PM -0700, SJ Park wrote: > > On Thu, 6 Aug 2026 12:05:00 -0500 Gregory Price wrote: > > > > > On Thu, Aug 06, 2026 at 02:37:59PM +0100, Lorenzo Stoakes (ARM) wrote: > > > > On Tue, Jul 28, 2026 at 03:47:11PM -0400, Gregory Price wrote: > > > > > All DAMON physical- and virtual-address operations obtain their folios > > > > > through damon_get_folio(). That helper already excludes ZONE_DEVICE > > > > > memory implicitly via pfn_to_online_page() and folio_test_lru(), but > > > > > this is inconsistent with other callers in mm/ which test explicitly. > > > > > > > > > > Add an explicit folio_is_zone_device() rejection in damon_get_folio() > > > > > so the guarantee lives in one place and covers every caller uniformly, > > > > > consistent with other mm walkers that reject zone device folios. > > > > > > > > > > Signed-off-by: Gregory Price (Meta) > > > > > > > > Thanks, nice to make it explicit! > > > > > > > > Acked-by: Lorenzo Stoakes (ARM) > > > > > > > > > > SJ Asked me to drop it, > > > > I didn't asked you to drop this. I asked your thought about revisioning this > > for my concern. And you replied [1] you can drop this. > > > > Sorry I didn't mean to imply you pushed for one side or another, just > that the feedback you gave about not wanting dead code is reason enough > to drop it. > > I will probably just go ahead and drop it unless Lorenzo thinks the > patch is worth keeping. In my next private node iteration, it ends up > back in anyway - so we get a two for one without the intermediate patch. Yeah it's damon code so if SJ isn't happy let's drop it for now and we can revisit later! > > ~Gregory -- Cheers, Lorenzo