diff options
Diffstat (limited to 'Documentation/x86/intel_rdt_ui.txt')
| -rw-r--r-- | Documentation/x86/intel_rdt_ui.txt | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/Documentation/x86/intel_rdt_ui.txt b/Documentation/x86/intel_rdt_ui.txt index 4d8848e4e224..71c30984e94d 100644 --- a/Documentation/x86/intel_rdt_ui.txt +++ b/Documentation/x86/intel_rdt_ui.txt @@ -7,15 +7,24 @@ Tony Luck <tony.luck@intel.com> Vikas Shivappa <vikas.shivappa@intel.com> This feature is enabled by the CONFIG_INTEL_RDT Kconfig and the -X86 /proc/cpuinfo flag bits "rdt", "cqm", "cat_l3" and "cdp_l3". +X86 /proc/cpuinfo flag bits: +RDT (Resource Director Technology) Allocation - "rdt_a" +CAT (Cache Allocation Technology) - "cat_l3", "cat_l2" +CDP (Code and Data Prioritization ) - "cdp_l3", "cdp_l2" +CQM (Cache QoS Monitoring) - "cqm_llc", "cqm_occup_llc" +MBM (Memory Bandwidth Monitoring) - "cqm_mbm_total", "cqm_mbm_local" +MBA (Memory Bandwidth Allocation) - "mba" To use the feature mount the file system: - # mount -t resctrl resctrl [-o cdp] /sys/fs/resctrl + # mount -t resctrl resctrl [-o cdp[,cdpl2]] /sys/fs/resctrl mount options are: "cdp": Enable code/data prioritization in L3 cache allocations. +"cdpl2": Enable code/data prioritization in L2 cache allocations. + +L2 and L3 CDP are controlled seperately. RDT features are orthogonal. A particular system may support only monitoring, only control, or both monitoring and control. @@ -87,6 +96,17 @@ with the following files: bytes) at which a previously used LLC_occupancy counter can be considered for re-use. +Finally, in the top level of the "info" directory there is a file +named "last_cmd_status". This is reset with every "command" issued +via the file system (making new directories or writing to any of the +control files). If the command was successful, it will read as "ok". +If the command failed, it will provide more information that can be +conveyed in the error returns from file operations. E.g. + + # echo L3:0=f7 > schemata + bash: echo: write error: Invalid argument + # cat info/last_cmd_status + mask f7 has non-consecutive 1-bits Resource alloc and monitor groups --------------------------------- @@ -651,7 +671,7 @@ occupancy of the real time threads on these cores. # mkdir p1 Move the cpus 4-7 over to p1 -# echo f0 > p0/cpus +# echo f0 > p1/cpus View the llc occupancy snapshot |