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 41D3E48BD24 for ; Tue, 5 May 2026 15:58:08 +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=1777996690; cv=none; b=W8kAY3Qc8743IKX+GZ8A7lY2zaBKaqA+LOa/xDsZ+9u7VML2Un9Zgkt0x/mHmP06DcoGnlzGTXL3z3DbjVK85ZpVGlLYSNePNls6e9vYcnMNPzncAPFGjU5Eews0HQ4zX6QeTv7r0lYT70Bkel6eS1QjKMnW4OwbtYXLw0Ywz1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777996690; c=relaxed/simple; bh=IEbO8c0VoV2wXdge73Q9P25Q8+7bAKUjsgH/T+KToAg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Nvi5UDysL+L6QcSDAi56A5UHPnpmYIriAceMQE1fIa4Om/p9j2cFbJUxiKcbQlQCYtc9ly6tIPFNpjAahPkESgKmhbX4/UFsGsSGNJ596La8bZJpPJ+qjWY2WEessTBcyHM+N93/Cto785/hGG9G3VdbE9oLqqzPZX0M5jQNKf4= 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=Wg5fHpXO; 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="Wg5fHpXO" 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 5C4BE302D; Tue, 5 May 2026 08:58:02 -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 975243F836; Tue, 5 May 2026 08:58:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1777996687; bh=IEbO8c0VoV2wXdge73Q9P25Q8+7bAKUjsgH/T+KToAg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wg5fHpXOX0EQrbcsdvpXmaQXs6MGiNdDmTJFV6efyEA0Ndstv2ykNR64cuSBU0rsn N72XqUCe/DKYd+o91J2vJ5Qvz89/tsjfxbVArhGVsg6Sh9kzx9l7+ksY7+2NLsSQrK 9ZsecD7LsYFnxVYs43lIqu/fGEEo+VsTRNWDR3uA= 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 v6 6/7] fs/resctrl: Document that automatic counter assignment is best effort Date: Tue, 5 May 2026 16:57:40 +0100 Message-ID: <20260505155741.3591201-7-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260505155741.3591201-1-ben.horgan@arm.com> References: <20260505155741.3591201-1-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 Reviewed-by: Reinette Chatre --- Changes since v4: Point user to mbm_L3_assignments rather than last_cmd_status (Reinette) Add "in all domains" (Reinette) Changes since v5: Add Reinette's R-b --- 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