From 9a1646211f8c67c7c98f8109607e3b962aea13eb Mon Sep 17 00:00:00 2001 From: Ben Horgan Date: Wed, 6 May 2026 09:28:54 +0100 Subject: [PATCH] fs/resctrl: Document that automatic counter assignment is best effort 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 Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Babu Moger Reviewed-by: Reinette Chatre Tested-by: Babu Moger Link: https://lore.kernel.org/20260506082855.3694761-1-ben.horgan@arm.com --- 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