From nobody Thu Apr 2 22:12:11 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 45FA140F8C2 for ; Thu, 26 Mar 2026 17:26:13 +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=1774545980; cv=none; b=bnIjdnUTqiVqj0Dy+VrTemGhRF02HIMEb6zo9FwfFN0U/ySOWr0eOBR/OFMDSJ9d09w3Cj1MKBfxc5MfXXuWdHb+h7wbCc2ELxjgu4u+JJF41ueIY0uDqIooeNS/osarIlw5W3wScPadWovaIWfamW8acg3o7GNd/GTrlF/D7l0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774545980; c=relaxed/simple; bh=eB4Cg1lvdQDq5ESyLcH3wG2Wkyfzy2z3s3q7NpvP/Fk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NgRg3xHLh5SUfKQ0h50/4W4hGHA6KFg0xiuBCDVYSEe3CpgXiM2T1X0Jc+Ar8T2YkR30qTv0LK+vt4YXbPAKPQcbGiJe6p6Csr6EHp2fLlUnhkB8wQ3CKPRfv1W/TwmS+cf0NTT2KCMHIta2L2N5cOf+P55JaSZALNPgm2QbllA= 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=Og1bG2nV; 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="Og1bG2nV" 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 69DED2BCB; Thu, 26 Mar 2026 10:26:06 -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 7F6163F641; Thu, 26 Mar 2026 10:26:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1774545972; bh=eB4Cg1lvdQDq5ESyLcH3wG2Wkyfzy2z3s3q7NpvP/Fk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Og1bG2nVs9nE/iekD0MYb80bNv07jI4IdBV2/owh6ztidFXjCG5gG3QeX3QN4uMz3 8AOq7okIc8A7pwesFvOiOvqn2yumnjqv9un8in0qt09aWeO3L3lsccSVRGfhWt0636 DL390z6IIXcLYQOaJltNUsml33cTl3grKxS7nFzY= 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 v4 6/7] fs/resctrl: Document that automatic counter assignment is best effort Date: Thu, 26 Mar 2026 17:25:50 +0000 Message-ID: <20260326172551.1553871-7-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260326172551.1553871-1-ben.horgan@arm.com> References: <20260326172551.1553871-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" 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 --- Hi Reinette, I've just taken your suggested paragraph with a minor tweak (s/scenario/a scenario/) and moved it above the examples as I think it makes sense to keep examples last in each section. --- Documentation/filesystems/resctrl.rst | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesyst= ems/resctrl.rst index ba609f8d4de5..68cada238844 100644 --- a/Documentation/filesystems/resctrl.rst +++ b/Documentation/filesystems/resctrl.rst @@ -472,6 +472,12 @@ with the following files: "1": Auto assignment is enabled. =20 + 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. Consult last_cmd_status + for details during such a scenario. + Example:: =20 # echo 0 > /sys/fs/resctrl/info/L3_MON/mbm_assign_on_mkdir --=20 2.43.0