From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2FEE91DEFFC; Tue, 11 Feb 2025 07:00:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739257206; cv=none; b=TDMe/0mI1PbxKhydBsluLX2t/wxuBVzfzolf0zUkqKzHpXPibhDkOk6pUNYYSCAfaEMV0/NbVrxJ7bqpZon/2GDLhv/tVUOk1nicwyxNtxB1CaC9fbJNmZsG23AisWIqVy+Cr/WEIST0yuTNuIdCUE/gXdto5eywvcPV6isY0Xg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739257206; c=relaxed/simple; bh=2Of0rA5FoGn4ZTHvRWUGZwrrx3D8metj3Q4juNaw1eM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=YzrkYROf7joycALfUXI7DFVDK7sBAq0Ce0l0C6oi/M+M9/FtLNj/DK2rxs3nrI862PcqnudO6rIJA5v46UMKdswrAAGI4N1wg91LDsdZbUrcd1UxvasVs/ZKvlOMw24mJZQwg8Odk73l9Cd9kfpfnuDS7GOPrFF8YZmz8ytMYbM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GI2gfjNc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GI2gfjNc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E770C4CEDD; Tue, 11 Feb 2025 07:00:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739257205; bh=2Of0rA5FoGn4ZTHvRWUGZwrrx3D8metj3Q4juNaw1eM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GI2gfjNcDnwg7GzDatzEEZWfdJYDwAQFrC79MEvER1PMZLr7IEBISVpIOBY+WVS/O Gv8Lp5iEfvSod7fn0czmeJmEGHThHHxD6wpiXBFV1nkPXHa9njgo6XN2sS6Rx4U67S sK63mMvK5ma/GUUgHThjzPIYwzhBUYy6KcmWJ2zWLBgCMb0O+5DZpMFv0OzEoV4Kmt B5434/VJqwbdrTCswBVUb0QbiYOXhnKk4JdWUR5CiSq6lfFLOFAyW6GydavzlbWW19 6gVh1UsyCquTPBGSNfLBRtN9/TduDjrWCgMDEVYeiuiF24cPFXuKgba7glsc/7wRYn KUj/R737RmeTQ== From: SeongJae Park To: David Hildenbrand Cc: SeongJae Park , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, nouveau@lists.freedesktop.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, damon@lists.linux.dev, Andrew Morton , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jonathan Corbet , Alex Shi , Yanteng Si , Karol Herbst , Lyude Paul , Danilo Krummrich , David Airlie , Simona Vetter , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , "Liam R. Howlett" , Lorenzo Stoakes , Vlastimil Babka , Jann Horn , Pasha Tatashin , Peter Xu , Alistair Popple , Jason Gunthorpe Subject: Re: [PATCH v2 15/17] mm/damon: handle device-exclusive entries correctly in damon_folio_mkold_one() Date: Mon, 10 Feb 2025 23:00:02 -0800 Message-Id: <20250211070002.6005-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250210193801.781278-16-david@redhat.com> References: Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Mon, 10 Feb 2025 20:37:57 +0100 David Hildenbrand wrote: > Ever since commit b756a3b5e7ea ("mm: device exclusive memory access") > we can return with a device-exclusive entry from page_vma_mapped_walk(). > > damon_folio_mkold_one() is not prepared for that and calls > damon_ptep_mkold() with PFN swap PTEs. Teach damon_ptep_mkold() to deal > with these PFN swap PTEs. Note that device-private entries are so far not > applicable on that path, as damon_get_folio() filters out non-lru > folios. > > Should we just skip PFN swap PTEs completely? Possible, but it seems > straight forward to just handle it correctly. > > Note that we could currently only run into this case with > device-exclusive entries on THPs. We still adjust the mapcount on > conversion to device-exclusive; this makes the rmap walk > abort early for small folios, because we'll always have > !folio_mapped() with a single device-exclusive entry. We'll adjust the > mapcount logic once all page_vma_mapped_walk() users can properly > handle device-exclusive entries. > > Signed-off-by: David Hildenbrand Reviewed-by: SeongJae Park Thanks, SJ [...]