From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794579955; b=ZYK7vYyNcX8CCtM7s/c6vBi/LbdnC3j+L2fqlQFK9wMqLFtcLbJIfFQAkszVTbJA0Mi2 8OAf6lwJi9pT9y03IfKhVsiboBEmpxbvicE4nY8e4nBg73JoVkdWc8q3k7NQqjw1lOfBc 6Z7WJdJBM18LdaROMn49cMPkBnLRhNbMtCaCxqujhyDqcC4uH4wdWka+s2NDrGthusATe fVhmseYUNDm+fEk0EixFmCTEFTOJdBJn9+qbkff22HwuDcJTm+/HGhm3toT1RKkLSdzRD DSKzpkRGaBnIwMaUvVpI5oel/wjSOAeNPDLZ5zkg3dkPzxI7nrZDqELr3zUDUT6x1dg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794579955; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=JKx96xT0irEgZmynXxaruuwq99BKK/Y5MEwjwUN2jM4=; b=g6W4Tn2z9Who0ZkTTwNW7yJhclxSY7OojV1rHUdmw/0xGz6kYbO59pPLwBe72aG3E51p nhORo899QFxn58K25tOjUL3Wp0zr3KQLibRiChzYVzndOdeDrZXSn1hvQL496tto86Xpq iNbBML0KRLPIKnE2kUN/XL1cq2vySKO3eFa4TfPH36c+DiKOIgsnXfGv9QuCevVDq5d8C npV4Qi0tgrboB4I/wO+pCwUar9TRNZbvpQem/LLPRMSKResc4Eo8vmmCT8lsnBYURi5RM X6eNoPZlabbKLHM6I+kQUEq+rs2GyYv4sjW0dXS6affNHGgnd4bHWjUzOvo0zY1feuQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=G2j7Yy2i; 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 A0AFF606A323 for ; Fri, 13 Nov 2026 14:25:55 +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=G2j7Yy2i Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C3501F000C4; Fri, 13 Nov 2026 14:25:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794579955; bh=JKx96xT0irEgZmynXxaruuwq99BKK/Y5MEwjwUN2jM4=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=G2j7Yy2iKLnP4Q0LhLtm5RIdpLoEtUQJqEFF0r99jDJYIjaGubzDRw8a85h5v7P3B wyjU7RsX0oiCWSqNE+fo5JNl3JpUjuGPbvilHm7ExUqBD/Nb49tbwLV8NqTz0CckFQ LZ54RELaNMiIjxGscCNkyT5nPU6qugoPyl2OLQNh2scybr3lkxf6lK5rEfLLNiY9pd t4rBErC9WzkIF8uDXwvyLXjb0LiyvEDSPERZbmhNc5FVdLTqURH0XVCR0KkuMLpOkG o6GonksQ1clDEDionU8mbBOUAx6EHeZ4G1Rpw9z/4ukBetC81LL/aB192z4Icrk6p+ SUOOohaFNfdOg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 3/9] mm/huge_memory: honor MM_CP_TRY_CHANGE_WRITABLE in change_huge_pud() Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?Q2FybG9zIEzDs3Bleg==?= Cc: linux-s390@vger.kernel.org, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261112142039.907090-5-clopez@suse.de> References: <20261112142039.907090-2-clopez@suse.de> <20261112142039.907090-5-clopez@suse.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 13 Nov 2026 14:25:54 +0000 X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > change_protection() applies vma->vm_page_prot, which lacks the write bit > for CoW and write-notified mappings. MM_CP_TRY_CHANGE_WRITABLE makes > entries writable again if a write fault would only set the write bit. >=20 > However, change_huge_pud() ignores the flag. For example, device DAX > mappings are write-notified once soft-dirty tracking is armed through > /proc/pid/clear_refs, and a protection change then leaves dirty PUDs > read-only, so the next write to each of them faults. >=20 > Fix this by adding can_change_pud_writable(), based on > can_change_pmd_writable(). It omits the NUMA and uffd-wp checks, as > change_huge_pud() bails out on those changes. >=20 > Signed-off-by: Carlos L=C3=B3pez Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261112142039.9070= 90-2-clopez@suse.de?part=3D3