From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- Documentation/admin-guide/perf/qcom_l3_pmu.rst | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/admin-guide/perf/qcom_l3_pmu.rst (limited to 'Documentation/admin-guide/perf/qcom_l3_pmu.rst') diff --git a/Documentation/admin-guide/perf/qcom_l3_pmu.rst b/Documentation/admin-guide/perf/qcom_l3_pmu.rst new file mode 100644 index 0000000000..a3d014a46b --- /dev/null +++ b/Documentation/admin-guide/perf/qcom_l3_pmu.rst @@ -0,0 +1,26 @@ +=========================================================================== +Qualcomm Datacenter Technologies L3 Cache Performance Monitoring Unit (PMU) +=========================================================================== + +This driver supports the L3 cache PMUs found in Qualcomm Datacenter Technologies +Centriq SoCs. The L3 cache on these SOCs is composed of multiple slices, shared +by all cores within a socket. Each slice is exposed as a separate uncore perf +PMU with device name l3cache__. User space is responsible +for aggregating across slices. + +The driver provides a description of its available events and configuration +options in sysfs, see /sys/devices/l3cache*. Given that these are uncore PMUs +the driver also exposes a "cpumask" sysfs attribute which contains a mask +consisting of one CPU per socket which will be used to handle all the PMU +events on that socket. + +The hardware implements 32bit event counters and has a flat 8bit event space +exposed via the "event" format attribute. In addition to the 32bit physical +counters the driver supports virtual 64bit hardware counters by using hardware +counter chaining. This feature is exposed via the "lc" (long counter) format +flag. E.g.:: + + perf stat -e l3cache_0_0/read-miss,lc/ + +Given that these are uncore PMUs the driver does not support sampling, therefore +"perf record" will not work. Per-task perf sessions are not supported. -- cgit v1.2.3