Re: [RFC PATCH 1/2] {topost} drivers/perf: hisi: Add description for HNS3 PMU driver
From: John Garry <hidden>
Date: 2021-03-25 15:17:40
On 22/03/2021 01:49, Guangbin Huang wrote:
please remove {topost} next time
HNS3 PMU End Point device is supported on HiSilicon HIP09 platform, so add document hns3-pmu.rst to provide guidance on how to use it.
sorry, I didn't do much review of this before sending out...
quoted hunk ↗ jump to hunk
Signed-off-by: Guangbin Huang <redacted> --- Documentation/admin-guide/perf/hns3-pmu.rst | 125 ++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) create mode 100644 Documentation/admin-guide/perf/hns3-pmu.rstdiff --git a/Documentation/admin-guide/perf/hns3-pmu.rst b/Documentation/admin-guide/perf/hns3-pmu.rst new file mode 100644 index 0000000..3597a8e --- /dev/null +++ b/Documentation/admin-guide/perf/hns3-pmu.rst@@ -0,0 +1,125 @@ +====================================== +HNS3 Performance Monitoring Unit (PMU) +====================================== + +HNS3(HiSilicon network system 3) Performance Monitoring Unit (PMU) is an +End Point device to collect performance statistics of HiSilicon SoC NIC. +On Hip09, each SICL has one PMU device.
Even though the hisi-pmu doc now mentions what is SICL, it is also better mention here what it is.
+ +HNS3 PMU is supported to collect performance statistics of bandwidth, +latency, packet rate and interrupt rate. + +Each HNS3 PMU supports up to 8 hardware events. + +HNS3 PMU driver +=============== + +The HNS3 PMU driver registers a perf PMU with the name of its device id.:: + + /sys/devices/hns3_pmu_<device_id>
any reason for which sicl is not used in the same? How is a anyone supposed to know which device hns3_pmu_0 - for example - is ?
+ +PMU driver provides description of available events, filter modes, format, +identifier and cpumask in sysfs. + +The "events" directory describes the event code and subevent code of all +supported events shown in perf list. + +The "filtermode" directory describes the supported filter modes of each +event. + +The "format" directory describes all formats of the config (events) and +config1 (filter options) fields of the perf_event_attr structure. + +The "identifier" file shows version of PMU hardware device. + +The "cpumask" file shows which CPU is PMU driver running on.
isn't that really the CPUs associated with that PMU?
+ +Example usage of checking event code and subevent code:: + + $# cat /sys/devices/hns3_pmu_0/events/bw_igu_ssu + event=0x0, subevent=0x0
as below
+ +Example usage of checking supported filter mode:: + + $# cat /sys/devices/hns3_pmu_0/filtermode/bw_igu_ssu + filter mode supported: global/port/port-tc/
A sysfs file should just hold a single value is a basic rule
+ +Example usage of perf:: + + $# perf list + hns3_pmu_0/bw_igu_ssu/ [kernel PMU event] + ------------------------------------------ + + $# perf stat -a -e hns3_pmu_0/bw_igu_ssu,global=1/ -I 1000 + or + $# perf stat -a -e hns3_pmu_0/event=0,subevent=0,global=1/ -I 1000 + +The current driver does not support sampling. So "perf record" is unsupported. +Also attach to a task is unsupported for HNS3 PMU. + +Filter modes +-------------- + +1. global mode +PMU collect performance statistic of all functions of IO DIE. Set the +"global" filter option to 1 will enable this mode. +Example usage of perf:: + + $# perf stat -a -e hns3_pmu_0/event=0,subevent=0,global=1/ -I 1000 + +2. port mode +PMU collect performance statistic of one whole physical port. The port id +is same as mac id. The "tc" filter option must be set to 0xF in this mode. +Example usage of perf:: + + $# perf stat -a -e hns3_pmu_0/event=0,subevent=0,port=0,tc=0xF/ -I 1000 + +3. port-tc mode +PMU collect performance statistic of one tc of physical port. The port id +is same as mac id. The "tc" filter option must be set to 0 ~ 7 in this +mode. +Example usage of perf:: + + $# perf stat -a -e hns3_pmu_0/event=0,subevent=0,port=0,tc=0/ -I 1000 + +4. func mode +PMU collect performance statistic of one PF/VF. The function id is BDF of +PF/VF, its conversion formula:: + + func = (bus << 8) + (device << 3) + (function) + +for example: + BDF func + 35:00.0 0x3500 + 35:00.1 0x3501 + 35:01.0 0x3508
any reason why we can't have each nibble holding a digit of BDF? 0x3508 look strange
+ +In this mode, the "queue" filter option must be set to 0xFFFF. +Example usage of perf:: + + $# perf stat -a -e hns3_pmu_0/event=0,subevent=0,func=0x3500,queue=0xFFFF/ -I 1000 + +5. func-queue mode +PMU collect performance statistic of one queue of PF/VF. The function id +is BDF of PF/VF, its conversion formula:: + + func = (bus << 8) + (device << 3) + (function) + +In this mode, the "queue" filter option must be set to the exact queue id +of function. +Example usage of perf:: + + $# perf stat -a -e hns3_pmu_0/event=0,subevent=0,func=0x3500,queue=0/ -I 1000 +
To me it's odd that the difference between func mode and func-queue mode is just setting the queue=0xffff or queue=0 - seems to be just the same mode with a different queue option
+ +6. func-intr mode +PMU collect performance statistic of one interrupt of PF/VF. The function +id is BDF of PF/VF, its conversion formula:: + + func = (bus << 8) + (device << 3) + (function) + +In this mode, the "intr" filter option must be set to the exact interrupt +id of function. +Example usage of perf:: + + $# perf stat -a -e hns3_pmu_0/event=0,subevent=0,func=0x3500,intr=0/ -I 1000
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