linux_dsm_epyc7002/tools/perf/Documentation
Andi Kleen 44b1e60ab5 perf stat: Basic support for TopDown in perf stat
Add basic plumbing for TopDown in perf stat

TopDown is intended to replace the frontend cycles idle/ backend cycles
idle metrics in standard perf stat output.  These metrics are not
reliable in many workloads, due to out of order effects.

This implements a new --topdown mode in perf stat (similar to
--transaction) that measures the pipe line bottlenecks using
standardized formulas. The measurement can be all done with 5 counters
(one fixed counter)

The result are four metrics:

FrontendBound, BackendBound, BadSpeculation, Retiring

that describe the CPU pipeline behavior on a high level.

The full top down methology has many hierarchical metrics.  This
implementation only supports level 1 which can be collected without
multiplexing. A full implementation of top down on top of perf is
available in pmu-tools toplev.  (http://github.com/andikleen/pmu-tools)

The current version works on Intel Core CPUs starting with Sandy Bridge,
and Atom CPUs starting with Silvermont.  In principle the generic
metrics should be also implementable on other out of order CPUs.

TopDown level 1 uses a set of abstracted metrics which are generic to
out of order CPU cores (although some CPUs may not implement all of
them):

  topdown-total-slots       Available slots in the pipeline
  topdown-slots-issued      Slots issued into the pipeline
  topdown-slots-retired     Slots successfully retired
  topdown-fetch-bubbles     Pipeline gaps in the frontend
  topdown-recovery-bubbles  Pipeline gaps during recovery
                            from misspeculation

These metrics then allow to compute four useful metrics:

FrontendBound, BackendBound, Retiring, BadSpeculation.

Add a new --topdown options to enable events.  When --topdown is
specified set up events for all topdown events supported by the kernel.
Add topdown-* as a special case to the event parser, as is needed for
all events containing -.

The actual code to compute the metrics is in follow-on patches.

v2: Use standard sysctl read function.
v3: Move x86 specific code to arch/
v4: Enable --metric-only implicitly for topdown.
v5: Add --single-thread option to not force per core mode
v6: Fix output order of topdown metrics
v7: Allow combining with -d
v8: Remove --single-thread again
v9: Rename functions, adding arch_ and topdown_.
v10: Expand man page and describe TopDown better
Paste intro into commit description.
Print error when malloc fails.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1464119559-17203-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-06-06 17:04:15 -03:00
..
android.txt perf tools: Add info about cross compiling for Android ARM 2012-10-31 12:17:49 -02:00
asciidoc.conf perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
Build.txt perf build: Add build documentation 2015-02-12 17:53:00 -03:00
callchain-overhead-calculation.txt perf tools: Document --children option in more detail 2015-04-29 10:38:06 -03:00
examples.txt perf record: Remove -f/--force option 2013-07-08 17:37:25 -03:00
intel-bts.txt perf tools: Add Intel BTS support 2015-08-21 11:34:10 -03:00
intel-pt.txt perf tools: Add support for skipping itrace instructions 2016-03-30 11:14:09 -03:00
itrace.txt perf tools: Add support for skipping itrace instructions 2016-03-30 11:14:09 -03:00
jit-interface.txt perf symbols: Add description of JIT interface 2012-08-13 14:55:02 -03:00
Makefile tools: Move utilities.mak from perf to tools/scripts/ 2016-03-18 13:57:20 -03:00
manpage-1.72.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
manpage-base.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
manpage-bold-literal.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
manpage-normal.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
manpage-suppress-sp.xsl perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
perf-annotate.txt perf tools: Make -f/--force option documentation consistent across tools 2016-03-30 11:14:08 -03:00
perf-archive.txt perf archive: Remove duplicated 'runs' in man page 2013-12-09 15:21:45 -03:00
perf-bench.txt perf bench mem: Rename 'routine' to 'function' 2015-10-19 16:10:25 -03:00
perf-buildid-cache.txt perf buildid-cache: Add --purge FILE to remove all caches of FILE 2015-02-27 15:52:33 -03:00
perf-buildid-list.txt perf report: Accept fifos as input file 2011-12-23 17:01:03 -02:00
perf-config.txt perf config: Add '--system' and '--user' options to select which config file is used 2016-02-12 10:54:46 -03:00
perf-data.txt perf data: Add perf data to CTF conversion support 2015-02-25 16:13:12 -03:00
perf-diff.txt perf tools: Make -f/--force option documentation consistent across tools 2016-03-30 11:14:08 -03:00
perf-evlist.txt perf evlist: Add --trace-fields option to show trace fields 2016-01-08 14:23:02 -03:00
perf-help.txt perf_counter tools: Move from Documentation/perf_counter/ to tools/perf/ 2009-06-06 20:33:43 +02:00
perf-inject.txt perf inject: Add jitdump mmap injection support 2016-02-05 09:46:45 -03:00
perf-kmem.txt perf kmem: Add --live option for current allocation stat 2015-05-04 13:34:47 -03:00
perf-kvm.txt perf tools: Configurable per thread proc map processing time out 2015-06-19 18:27:13 -03:00
perf-list.txt perf list: Document event specifications better 2016-04-06 11:19:18 -03:00
perf-lock.txt perf lock: Account for lock average wait time 2013-10-09 11:24:01 -03:00
perf-mem.txt perf mem: Add -U/-K (--all-user/--all-kernel) options 2016-03-30 11:14:07 -03:00
perf-probe.txt perf probe: Add --no-inlines option to avoid searching inline functions 2015-05-08 16:26:44 -03:00
perf-record.txt perf record: Disable buildid cache options by default in switch output mode 2016-04-28 09:58:59 -03:00
perf-report.txt perf report: Add srcline_from/to branch sort keys 2016-05-23 11:25:16 -03:00
perf-sched.txt perf sched map: Display only given cpus 2016-04-13 10:11:52 -03:00
perf-script-perl.txt perf Documentation: Fix typos in perf/Documentation 2014-10-15 17:39:02 -03:00
perf-script-python.txt perf Documentation: Fix typos in perf/Documentation 2014-10-15 17:39:02 -03:00
perf-script.txt perf tools: Fix usage of max_stack sysctl 2016-05-20 11:43:56 -03:00
perf-stat.txt perf stat: Basic support for TopDown in perf stat 2016-06-06 17:04:15 -03:00
perf-test.txt perf Documentation: Fix typos in perf/Documentation 2014-10-15 17:39:02 -03:00
perf-timechart.txt perf timechart: Add more options to IO mode 2014-07-10 00:22:54 +02:00
perf-top.txt perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack 2016-04-27 10:29:07 -03:00
perf-trace.txt perf tools: Fix usage of max_stack sysctl 2016-05-20 11:43:56 -03:00
perf.txt perf tools: Handle -h and -v options 2015-10-05 16:36:18 -03:00
perfconfig.example perf annotate: Rename 'colors.code' to 'colors.jump_arrows' 2016-01-26 11:52:46 -03:00
tips.txt perf report: Add --hierarchy option 2016-02-24 20:21:15 -03:00