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=1793112083; b=xeqxKv0zDcEeCCyZMFhfD/kc+G6gIIRLwlLls5N0413lOL2bqaLNID3vuW09U+8J6geT YTSWBJ3kpMdRqeB710qnBygxeDidMFfqJOrLz/kInYIhIZi9tBVjzDdZ3a4ZWrZsYgEwK 66xwiyALgFWkwEf2gUb0CqEaJV+GKoyRyQmB8Uimz+SJk5Tf5mQliG9fLCnaro55SEYjY zlOxC74fF8fOF0M/7xbkiQOXNM0iNOsEKCNRmr+li/yBbSliHPRjCzIIsLFImQNW/BRe2 mhpTnwA9sW45tetiFd7PcewiuMjrLC2sPZQ7Q5ENcymu1lYk7op0vz+RSLQV/k9FqjA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793112083; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=v8oGnKqxc51XmXaLSYVMWsoJS5Na61fScx5RhHHxZNM=; b=k8HYSq2wWQMK9pYfzAbxRmDrl7zeeqBeOWMDjT0lCzxddLFdziE3de5NQRoICD88sk1V OKDeRgISJbX3rAhq0vW8i0AGYTsHjYI9fjnoI+06XyNErevsTXpEIqOjcWWG4kVEIQ1bf +Y4uaHaSDMdzE88UqRJr6qc6w+0YCRZLVzlFVv/J/rQlCqfkGIkEGGrnZneXi3lAQB+rW JxzxIZJrJ8C14T9Q0JqEuA4luw03/zN/oE49pMDWoQbxqUFJlO8/Un0lIFQ8KheSbKmUj fVua4Bpwge/VB02VB1h7JLSOgmfnM989zCuu0sa8xDeV8kgikkIsDwmPw225LYxqbIw== 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=V+OOEcnq; 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 3DB8A606BA50 for ; Tue, 27 Oct 2026 14:41:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=V+OOEcnq Received: by smtp.kernel.org (Postfix) with ESMTPSA id A01421F01829; Tue, 27 Oct 2026 14:41:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793112082; bh=v8oGnKqxc51XmXaLSYVMWsoJS5Na61fScx5RhHHxZNM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=V+OOEcnqdokWsFx73o9vakqWZrPhXIRRiopYfzWZn7GXN1qsiz6Tqdn2xdoZcEGPx /ChPoOI7FrQY8nOTHdYySHX2rEXemr3n/hpNmjr8utv0vcKHtl4TbBuNvh0TasEjdc Ud4cZ4ZWYI8D71MMjjyoJQLhpm3zVZkJ227tEvwccZs0E3P2XHYJftHgMFjZzSMaZa r40kF5Yw0sK1F2sfbTIInZIjcijyK9teNkL7oCrsksNx3nvKJgc5wsiWhlQ/F2uZIy gYiEGQNfXkti6GPyd1G7sgsHTxSAb/zH40i0UT5AmGcM82b3Dof5v2+Gjjjf8I2lCF ECRRKeVS0mmqA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 10/10] s390/maccess: Remove spinlock from __s390_kernel_write() Reply-To: sashiko-reviews@lists.linux.dev To: "Heiko Carstens" Cc: linux-s390@vger.kernel.org, "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261027143030.3154657-11-hca@linux.ibm.com> References: <20261027143030.3154657-1-hca@linux.ibm.com> <20261027143030.3154657-11-hca@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 27 Oct 2026 14:41:22 +0000 X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > The spinlock in __s390_kernel_write() was introduced to serialize the > read-modify-write sequence against concurrent callers. Now that all > runtime callers of s390_kernel_write() hold the text_mutex, the > spinlock is not required anymore. >=20 > Replace it with preempt_disable() / preempt_enable() and sync_core(). > Previously, CPU serialization was implicitly done by other > instructions. Make this explicit with sync_core() instead of > relying on that. >=20 > Preemption is disabled so that sync_core() issues the CPU serialization > instruction on the same CPU that executed the stores. This completes all > previous stores and makes them visible to other CPUs. >=20 > Other CPUs need to perform CPU serialization, e.g. with text_poke_sync(), > [ ... ] > Work around that by calling the non-checking __s390_kernel_write(), > and add lockdep_assert_held() checks to arch_arm_kprobe() and > arch_disarm_kprobe(). >=20 > Signed-off-by: Heiko Carstens Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261027143030.3154= 657-1-hca@linux.ibm.com?part=3D10