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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lZO8K1dU; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5089606A8B4; Thu, 12 Nov 2026 09:01:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lZO8K1dU Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95AB51F00A05; Thu, 12 Nov 2026 09:01:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794474084; bh=bu4BdULQIHQlhCcJutXTiMEZNYcwzWTKws8acbVlwyE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=lZO8K1dUoIbaKau1/mQ2XLHj8U7HPGcOc+Jg3qG1bBjqPSXKQuPt5bBUVqkR43GNR XbNj3yVFbPmlnKpom5Fxsn1EfnG8ogso6U83ClsEGmX8xmbdlboqZTq/00tV1jBWkG El1lZn5FUCjN0qLn4AcbgEIKiLv26Zf5ZqQxI2rt27EuwkZ+u4hVATLH3ReQVTG5JT tPYyAH++YbVOWgUKiM3fXw5bBc+Oizv+ZbST6ZIfQO5hvA3Wfzvhz4yHOWRnF0KEG4 lY4wumFPxplRHKvViXKZUXNXdpHNqKNUhadQoF8XC8Eyeg9BPqfr1XbjFo3WTF4Fnx 4oQ9xVunb02EA== Message-ID: <3973721c-9524-4a08-9929-e88617d21961@kernel.org> Date: Thu, 12 Nov 2026 10:00:59 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] fs/proc/task_mmu: account device-private PMDs as present in smaps To: Usama Arif , Andrew Morton , apopple@nvidia.com, byungchul@sk.com, gourry@gourry.net, jannh@google.com, joshua.hahnjy@gmail.com, liam@infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, matthew.brost@intel.com, mhocko@suse.com, pfalcato@suse.de, rppt@kernel.org, surenb@google.com, vbabka@kernel.org, ying.huang@linux.alibaba.com, ziy@nvidia.com, kas@kernel.org, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, kernel-team@meta.com, baolin.wang@linux.alibaba.com, Nico Pache , ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev Cc: stable@vger.kernel.org References: <20261111113904.650722-1-usama.arif@linux.dev> <20261111113904.650722-4-usama.arif@linux.dev> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/11/26 12:38, Usama Arif wrote: > Device-private PMDs represent mapped pages, but smaps_pmd_entry() > passes present=false to smaps_account(). That treats them like migration > entries: mapcounts are ignored, PSS is charged in full, and exclusive > mappings are accounted as shared. > > Match smaps_pte_entry() and mark device-private PMDs as present so > smaps_account() uses mapcounts for PSS and private/shared accounting. > > Fixes: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone device pages") > Cc: stable@vger.kernel.org > Signed-off-by: Usama Arif > --- > fs/proc/task_mmu.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index c0d391186c2b8..ad97532fc1184 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -1032,8 +1032,11 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, > } else if (unlikely(thp_migration_supported())) { > const softleaf_t entry = softleaf_from_pmd(*pmd); > > - if (softleaf_has_pfn(entry)) > + if (softleaf_has_pfn(entry)) { > + if (softleaf_is_device_private(entry)) > + present = true; > page = softleaf_to_page(entry); > + } > } I think I even spelled that out somewhere at some point while touching that code ... or did I fix the smaps_pte_entry() thing at some point? "present" is a bit misleading in general, because it's not pte_present() ... Matches smaps_pte_entry() Acked-by: David Hildenbrand (Arm) -- Cheers, David