From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 74A3F42EEA3 for ; Tue, 28 Apr 2026 13:04:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777381488; cv=none; b=VxWmEg8W4HfXw2ib1c0u2IDKfa2kMYsW9c0bfPvr0bUZZ3O8PMCPQYz9MNvMbJp9vKN7pyhVIKxu4tlTSkXlnzpdhed5v2ohdzFjRfwjMaPgJodheaGghku5KVt/GcGY5YR8S18fH4YhqCSoUrpjwiDqGfHJBESOCJjADO8voWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777381488; c=relaxed/simple; bh=D2aLxK7oRB9qdKyFOh0Vi4H13dpDMXTo3n9ovdW+Jj0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IKp8J6Lr+t7L1DxLBThjRONd6XvVuJ1nu+HY0YvCvpCl2izsR/Cw8bE8fSW6IOSlOWPAKiuCrvfbl1JlgylA2fYCcm3vCEPzUtqWOArA7hU4MiaAQXk+u9ZiXwBLRh1lEgB2pu6YTGQdbBatea/67x0/CQIlXuZWZ1xqk1iewu0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=rYj8GN7T; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="rYj8GN7T" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6C7702C1E; Tue, 28 Apr 2026 06:04:41 -0700 (PDT) Received: from e134344.cambridge.arm.com (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C37863F62B; Tue, 28 Apr 2026 06:04:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1777381486; bh=D2aLxK7oRB9qdKyFOh0Vi4H13dpDMXTo3n9ovdW+Jj0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rYj8GN7T0k1JfeDaEPV04AwUKQf+jIqmm//sAECkK4Eauy86ACGTLMC0XK3d+9v5O Lgl0IyP0iONVFkA1XRum/GYmrGvcu0ZRZCmQPJY7RcUevqKQuM9rvzU2dMk9TtG+Hb puJsCkdTANagME1C/XjmZGg+9+sQ7rLUow1V4PUQ= From: Ben Horgan To: linux-kernel@vger.kernel.org Cc: tony.luck@intel.com, reinette.chatre@intel.com, Dave.Martin@arm.com, james.morse@arm.com, babu.moger@amd.com, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, ben.horgan@arm.com, fenghuay@nvidia.com, tan.shaopeng@fujitsu.com Subject: [PATCH v5 6/7] fs/resctrl: Document that automatic counter assignment is best effort Date: Tue, 28 Apr 2026 14:04:21 +0100 Message-ID: <20260428130422.2287302-7-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260428130422.2287302-1-ben.horgan@arm.com> References: <20260428130422.2287302-1-ben.horgan@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When using automatic counter assignment it's useful for a user to know which counters they can expect to be assigned on group creation. Document that automatic counter assignment is best effort and how to discover any assignment failures. Suggested-by: Reinette Chatre Signed-off-by: Ben Horgan --- Changes since v4: Point user to mbm_L3_assignments rather than last_cmd_status (Reinette) Add "in all domains" (Reinette) --- Documentation/filesystems/resctrl.rst | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst index 2898a51e6f4b..b388e9193896 100644 --- a/Documentation/filesystems/resctrl.rst +++ b/Documentation/filesystems/resctrl.rst @@ -479,6 +479,12 @@ with the following files: "1": Auto assignment is enabled. + Automatic counter assignment is done with best effort. If auto + assignment is enabled but there are not enough available counters then + monitor group creation could succeed while one or more events belonging + to the group may not have a counter assigned in all domains. Consult + mbm_L3_assignments for counter assignment states of the new groups. + Example:: # echo 0 > /sys/fs/resctrl/info/L3_MON/mbm_assign_on_mkdir -- 2.43.0