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authorLinus Torvalds2019-07-16 21:21:41 +0200
committerLinus Torvalds2019-07-16 21:21:41 +0200
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tree11893170f5c246bb0dee8066e85878af04162ab0 /Documentation/admin-guide/perf/thunderx2-pmu.rst
parentMerge tag 'xtensa-20190715' of git://github.com/jcmvbkbc/linux-xtensa (diff)
parentdocs: kbuild: fix build with pdf and fix some minor issues (diff)
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Merge tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull rst conversion of docs from Mauro Carvalho Chehab: "As agreed with Jon, I'm sending this big series directly to you, c/c him, as this series required a special care, in order to avoid conflicts with other trees" * tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (77 commits) docs: kbuild: fix build with pdf and fix some minor issues docs: block: fix pdf output docs: arm: fix a breakage with pdf output docs: don't use nested tables docs: gpio: add sysfs interface to the admin-guide docs: locking: add it to the main index docs: add some directories to the main documentation index docs: add SPDX tags to new index files docs: add a memory-devices subdir to driver-api docs: phy: place documentation under driver-api docs: serial: move it to the driver-api docs: driver-api: add remaining converted dirs to it docs: driver-api: add xilinx driver API documentation docs: driver-api: add a series of orphaned documents docs: admin-guide: add a series of orphaned documents docs: cgroup-v1: add it to the admin-guide book docs: aoe: add it to the driver-api book docs: add some documentation dirs to the driver-api book docs: driver-model: move it to the driver-api book docs: lp855x-driver.rst: add it to the driver-api book ...
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+=============================================================
+Cavium ThunderX2 SoC Performance Monitoring Unit (PMU UNCORE)
+=============================================================
+
+The ThunderX2 SoC PMU consists of independent, system-wide, per-socket
+PMUs such as the Level 3 Cache (L3C) and DDR4 Memory Controller (DMC).
+
+The DMC has 8 interleaved channels and the L3C has 16 interleaved tiles.
+Events are counted for the default channel (i.e. channel 0) and prorated
+to the total number of channels/tiles.
+
+The DMC and L3C support up to 4 counters. Counters are independently
+programmable and can be started and stopped individually. Each counter
+can be set to a different event. Counters are 32-bit and do not support
+an overflow interrupt; they are read every 2 seconds.
+
+PMU UNCORE (perf) driver:
+
+The thunderx2_pmu driver registers per-socket perf PMUs for the DMC and
+L3C devices. Each PMU can be used to count up to 4 events
+simultaneously. The PMUs provide a description of their available events
+and configuration options under sysfs, see
+/sys/devices/uncore_<l3c_S/dmc_S/>; S is the socket id.
+
+The driver does not support sampling, therefore "perf record" will not
+work. Per-task perf sessions are also not supported.
+
+Examples::
+
+ # perf stat -a -e uncore_dmc_0/cnt_cycles/ sleep 1
+
+ # perf stat -a -e \
+ uncore_dmc_0/cnt_cycles/,\
+ uncore_dmc_0/data_transfers/,\
+ uncore_dmc_0/read_txns/,\
+ uncore_dmc_0/write_txns/ sleep 1
+
+ # perf stat -a -e \
+ uncore_l3c_0/read_request/,\
+ uncore_l3c_0/read_hit/,\
+ uncore_l3c_0/inv_request/,\
+ uncore_l3c_0/inv_hit/ sleep 1