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| author | Haifeng Xu <haifeng.xu@shopee.com> | 2024-04-08 12:23:03 +0300 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-04-24 15:24:48 +0300 |
| commit | 931be446c6cbc15691dd499957e961f4e1d56afb (patch) | |
| tree | 5244e1021c9607b551d545716e6f58ba1da7d621 /Documentation/arch | |
| parent | 87739229485ac724849178eb6c35e38c6161eb77 (diff) | |
| download | linux-931be446c6cbc15691dd499957e961f4e1d56afb.tar.xz | |
x86/resctrl: Add tracepoint for llc_occupancy tracking
In our production environment, after removing monitor groups, those
unused RMIDs get stuck in the limbo list forever because their
llc_occupancy is always larger than the threshold. But the unused RMIDs
can be successfully freed by turning up the threshold.
In order to know how much the threshold should be, perf can be used to
acquire the llc_occupancy of RMIDs in each rdt domain.
Instead of using perf tool to track llc_occupancy and filter the log
manually, it is more convenient for users to use tracepoint to do this
work. So add a new tracepoint that shows the llc_occupancy of busy RMIDs
when scanning the limbo list.
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240408092303.26413-3-haifeng.xu@shopee.com
Diffstat (limited to 'Documentation/arch')
| -rw-r--r-- | Documentation/arch/x86/resctrl.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst index 6c245582d8fb..627e23869bca 100644 --- a/Documentation/arch/x86/resctrl.rst +++ b/Documentation/arch/x86/resctrl.rst @@ -446,6 +446,12 @@ during mkdir. max_threshold_occupancy is a user configurable value to determine the occupancy at which an RMID can be freed. +The mon_llc_occupancy_limbo tracepoint gives the precise occupancy in bytes +for a subset of RMID that are not immediately available for allocation. +This can't be relied on to produce output every second, it may be necessary +to attempt to create an empty monitor group to force an update. Output may +only be produced if creation of a control or monitor group fails. + Schemata files - general concepts --------------------------------- Each line in the file describes one resource. The line starts with |