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 43C1A42A799; Thu, 6 Aug 2026 14:05:05 +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=1786025109; cv=none; b=shPBwSu4x9NvNfa3o04iyi6OgjDH7Pt5WEM9fvUBLF+vF75gGX3s4Jw8sE94v28PhRgiLlS9NErj6HzKlxT75/zXLJkIcf4xLHeYW1qtW169PAcHmXSNkB4LB3+KLpR9/Sj9lWaQ8nuTvHJcHkB4+4j4utZl77jnykLQvPmrBMg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786025109; c=relaxed/simple; bh=Fej4wBcyVRGzr1QEv/2XxqD+1vELPvYsduCszLBHAcA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nqR3J0sBb6Z7aBIK6NArvFXhjUVIzTGnKdvNNFqyPOfqjYmoW3p9QP/XNQGddlydN9+K6JSkghFnoxO8k57vuXQcpGmxdM1IO2XNT4ba+3TvqSoOGfU6vtPATZqCBuSFfoX83+qJkofjRHeJf1ekEn4p3M2CL/5+cFin6dFDiIY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e7uNVDin; 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="e7uNVDin" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A35F1F000E9; Thu, 6 Aug 2026 14:04:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786025102; bh=Y6APqpoAC3496oI8IPDgumvxehVxwgctdvlogEWJB54=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=e7uNVDinolId4oTkkdWmLABrN7spjecvFSAiaGhptvu+n+kbdbWcmCcSmzLfmrtba Sipuirytwl0u7KG8zwUJ7JOH9qDbSKgVSB7yWU23pRUQGY1SjR4Ky2075A642KcR+d LC8t37EWOQ6t3y+k/TxyaZF6ZQLaguCMGda3y084/E+y6JS1oKXp1VyyzXRfzWDKzO 8PdaFkqMFd6ja8+epLmFc+Or+hozyPpNPP0K6dLNyhSQrJDIx+f32ATANefVs954KO q8AMAsfmd5cyfTswesD4Em2OpTCEwqsLe65KOP7EAUoVA9H7FVUKkeq8bSlnV/1Pzt vwJwAmtToXmSA== Date: Thu, 6 Aug 2026 15:04:42 +0100 From: "Lorenzo Stoakes (ARM)" To: Gregory Price Cc: linux-mm@kvack.org, damon@lists.linux.dev, linux-kernel@vger.kernel.org, kernel-team@meta.com, sj@kernel.org, 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 3/4] mm/madvise: skip zone device folios in cold/pageout PMD range Message-ID: References: <20260728194714.3713735-1-gourry@gourry.net> <20260728194714.3713735-4-gourry@gourry.net> 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: <20260728194714.3713735-4-gourry@gourry.net> On Tue, Jul 28, 2026 at 03:47:13PM -0400, Gregory Price wrote: > madvise_cold_or_pageout_pte_range() resolves the folio backing a PMD > via pmd_folio() and ages or reclaims it without checking for zone > device memory. > > The surrounding guards do not cover every zone device case: > > - can_madv_lru_vma() excludes VM_PFNMAP and VM_HUGETLB VMAs > (so device DAX is filtered) > > - !pmd_present() branch above rejects device-private and > migration entries, which are non-present. > > - A present zone device PMD - e.g. a device-coherent THP - is > not filtered by any of these, nor by pmd_folio() (unlike > vm_normal_page_pmd(), it performs no special/pfnmap check), > and would be aged or paged out here. > > Skip ZONE_DEVICE folios explicitly during MADV_COLD/PAGEOUT. > > Signed-off-by: Gregory Price (Meta) LGTM so: Reviewed-by: Lorenzo Stoakes (ARM) > --- > mm/madvise.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/madvise.c b/mm/madvise.c > index 07a21ca31bad..ffd6a68320a8 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -395,6 +395,9 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, > > folio = pmd_folio(orig_pmd); > > + if (folio_is_zone_device(folio)) > + goto huge_unlock; > + > /* Do not interfere with other mappings of this folio */ > if (folio_maybe_mapped_shared(folio)) > goto huge_unlock; > -- > 2.55.0 > -- Cheers, Lorenzo