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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-27 13:42:32 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-27 13:42:32 -0700 |
commit | 7b58b82b86c8b65a2b57a4c6cb96a460654f9e09 (patch) | |
tree | a13e19f216389f16f1cb6641d54751f167482515 /tools/perf/Documentation/perf-ftrace.txt | |
parent | Merge tag 'memblock-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock (diff) | |
parent | perf evsel: Improve AMD IBS (Instruction-Based Sampling) error handling messages (diff) | |
download | linux-dev-7b58b82b86c8b65a2b57a4c6cb96a460654f9e09.tar.xz linux-dev-7b58b82b86c8b65a2b57a4c6cb96a460654f9e09.zip |
Merge tag 'perf-tools-for-v5.18-2022-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Pull perf tools updates from Arnaldo Carvalho de Melo:
"New features:
perf ftrace:
- Add -n/--use-nsec option to the 'latency' subcommand.
Default: usecs:
$ sudo perf ftrace latency -T dput -a sleep 1
# DURATION | COUNT | GRAPH |
0 - 1 us | 2098375 | ############################# |
1 - 2 us | 61 | |
2 - 4 us | 33 | |
4 - 8 us | 13 | |
8 - 16 us | 124 | |
16 - 32 us | 123 | |
32 - 64 us | 1 | |
64 - 128 us | 0 | |
128 - 256 us | 1 | |
256 - 512 us | 0 | |
Better granularity with nsec:
$ sudo perf ftrace latency -T dput -a -n sleep 1
# DURATION | COUNT | GRAPH |
0 - 1 us | 0 | |
1 - 2 ns | 0 | |
2 - 4 ns | 0 | |
4 - 8 ns | 0 | |
8 - 16 ns | 0 | |
16 - 32 ns | 0 | |
32 - 64 ns | 0 | |
64 - 128 ns | 1163434 | ############## |
128 - 256 ns | 914102 | ############# |
256 - 512 ns | 884 | |
512 - 1024 ns | 613 | |
1 - 2 us | 31 | |
2 - 4 us | 17 | |
4 - 8 us | 7 | |
8 - 16 us | 123 | |
16 - 32 us | 83 | |
perf lock:
- Add -c/--combine-locks option to merge lock instances in the same
class into a single entry.
# perf lock report -c
Name acquired contended avg wait(ns) total wait(ns) max wait(ns) min wait(ns)
rcu_read_lock 251225 0 0 0 0 0
hrtimer_bases.lock 39450 0 0 0 0 0
&sb->s_type->i_l... 10301 1 662 662 662 662
ptlock_ptr(page) 10173 2 701 1402 760 642
&(ei->i_block_re... 8732 0 0 0 0 0
&xa->xa_lock 8088 0 0 0 0 0
&base->lock 6705 0 0 0 0 0
&p->pi_lock 5549 0 0 0 0 0
&dentry->d_lockr... 5010 4 1274 5097 1844 789
&ep->lock 3958 0 0 0 0 0
- Add -F/--field option to customize the list of fields to output:
$ perf lock report -F contended,wait_max -k avg_wait
Name contended max wait(ns) avg wait(ns)
slock-AF_INET6 1 23543 23543
&lruvec->lru_lock 5 18317 11254
slock-AF_INET6 1 10379 10379
rcu_node_1 1 2104 2104
&dentry->d_lockr... 1 1844 1844
&dentry->d_lockr... 1 1672 1672
&newf->file_lock 15 2279 1025
&dentry->d_lockr... 1 792 792
- Add --synth=no option for record, as there is no need to symbolize,
lock names comes from the tracepoints.
perf record:
- Threaded recording, opt-in, via the new --threads command line
option.
- Improve AMD IBS (Instruction-Based Sampling) error handling
messages.
perf script:
- Add 'brstackinsnlen' field (use it with -F) for branch stacks.
- Output branch sample type in 'perf script'.
perf report:
- Add "addr_from" and "addr_to" sort dimensions.
- Print branch stack entry type in 'perf report --dump-raw-trace'
- Fix symbolization for chrooted workloads.
Hardware tracing:
Intel PT:
- Add CFE (Control Flow Event) and EVD (Event Data) packets support.
- Add MODE.Exec IFLAG bit support.
Explanation about these features from the "Intel® 64 and IA-32
architectures software developer’s manual combined volumes: 1, 2A,
2B, 2C, 2D, 3A, 3B, 3C, 3D, and 4" PDF at:
https://cdrdv2.intel.com/v1/dl/getContent/671200
At page 3951:
"32.2.4
Event Trace is a capability that exposes details about the
asynchronous events, when they are generated, and when their
corresponding software event handler completes execution. These
include:
o Interrupts, including NMI and SMI, including the interrupt
vector when defined.
o Faults, exceptions including the fault vector.
- Page faults additionally include the page fault address,
when in context.
o Event handler returns, including IRET and RSM.
o VM exits and VM entries.¹
- VM exits include the values written to the “exit reason”
and “exit qualification” VMCS fields. INIT and SIPI events.
o TSX aborts, including the abort status returned for the RTM
instructions.
o Shutdown.
Additionally, it provides indication of the status of the
Interrupt Flag (IF), to indicate when interrupts are masked"
ARM CoreSight:
- Use advertised caps/min_interval as default sample_period on ARM
spe.
- Update deduction of TRCCONFIGR register for branch broadcast on
ARM's CoreSight ETM.
Vendor Events (JSON):
Intel:
- Update events and metrics for: Alderlake, Broadwell, Broadwell DE,
BroadwellX, CascadelakeX, Elkhartlake, Bonnell, Goldmont,
GoldmontPlus, Westmere EP-DP, Haswell, HaswellX, Icelake, IcelakeX,
Ivybridge, Ivytown, Jaketown, Knights Landing, Nehalem EP,
Sandybridge, Silvermont, Skylake, Skylake Server, SkylakeX,
Tigerlake, TremontX, Westmere EP-SP, and Westmere EX.
ARM:
- Add support for HiSilicon CPA PMU aliasing.
perf stat:
- Fix forked applications enablement of counters.
- The 'slots' should only be printed on a different order than the
one specified on the command line when 'topdown' events are
present, fix it.
Miscellaneous:
- Sync msr-index, cpufeatures header files with the kernel sources.
- Stop using some deprecated libbpf APIs in 'perf trace'.
- Fix some spelling mistakes.
- Refactor the maps pointers usage to pave the way for using refcount
debugging.
- Only offer the --tui option on perf top, report and annotate when
perf was built with libslang.
- Don't mention --to-ctf in 'perf data --help' when not linking with
the required library, libbabeltrace.
- Use ARRAY_SIZE() instead of ad hoc equivalent, spotted by
array_size.cocci.
- Enhance the matching of sub-commands abbreviations:
'perf c2c rec' -> 'perf c2c record'
'perf c2c recport -> error
- Set build-id using build-id header on new mmap records.
- Fix generation of 'perf --version' string.
perf test:
- Add test for the arm_spe event.
- Add test to check unwinding using fame-pointer (fp) mode on arm64.
- Make metric testing more robust in 'perf test'.
- Add error message for unsupported branch stack cases.
libperf:
- Add API for allocating new thread map array.
- Fix typo in perf_evlist__open() failure error messages in libperf
tests.
perf c2c:
- Replace bitmap_weight() with bitmap_empty() where appropriate"
* tag 'perf-tools-for-v5.18-2022-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (143 commits)
perf evsel: Improve AMD IBS (Instruction-Based Sampling) error handling messages
perf python: Add perf_env stubs that will be needed in evsel__open_strerror()
perf tools: Enhance the matching of sub-commands abbreviations
libperf tests: Fix typo in perf_evlist__open() failure error messages
tools arm64: Import cputype.h
perf lock: Add -F/--field option to control output
perf lock: Extend struct lock_key to have print function
perf lock: Add --synth=no option for record
tools headers cpufeatures: Sync with the kernel sources
tools headers cpufeatures: Sync with the kernel sources
perf stat: Fix forked applications enablement of counters
tools arch x86: Sync the msr-index.h copy with the kernel sources
perf evsel: Make evsel__env() always return a valid env
perf build-id: Fix spelling mistake "Cant" -> "Can't"
perf header: Fix spelling mistake "could't" -> "couldn't"
perf script: Add 'brstackinsnlen' for branch stacks
perf parse-events: Move slots only with topdown
perf ftrace latency: Update documentation
perf ftrace latency: Add -n/--use-nsec option
perf tools: Fix version kernel tag
...
Diffstat (limited to 'tools/perf/Documentation/perf-ftrace.txt')
-rw-r--r-- | tools/perf/Documentation/perf-ftrace.txt | 75 |
1 files changed, 52 insertions, 23 deletions
diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index 6e82b7cc0bf0..df4595563801 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -9,32 +9,24 @@ perf-ftrace - simple wrapper for kernel's ftrace functionality SYNOPSIS -------- [verse] -'perf ftrace' <command> +'perf ftrace' {trace|latency} <command> DESCRIPTION ----------- -The 'perf ftrace' command is a simple wrapper of kernel's ftrace -functionality. It only supports single thread tracing currently and -just reads trace_pipe in text and then write it to stdout. +The 'perf ftrace' command provides a collection of subcommands which use +kernel's ftrace infrastructure. -The following options apply to perf ftrace. + 'perf ftrace trace' is a simple wrapper of the ftrace. It only supports + single thread tracing currently and just reads trace_pipe in text and then + write it to stdout. -OPTIONS -------- + 'perf ftrace latency' calculates execution latency of a given function + (optionally with BPF) and display it as a histogram. --t:: ---tracer=:: - Tracer to use when neither -G nor -F option is not - specified: function_graph or function. +The following options apply to perf ftrace. --v:: ---verbose:: - Increase the verbosity level. - --F:: ---funcs:: - List available functions to trace. It accepts a pattern to - only list interested functions. +COMMON OPTIONS +-------------- -p:: --pid=:: @@ -43,10 +35,6 @@ OPTIONS --tid=:: Trace on existing thread id (comma separated list). --D:: ---delay:: - Time (ms) to wait before starting tracing after program start. - -a:: --all-cpus:: Force system-wide collection. Scripts run without a <command> @@ -61,6 +49,28 @@ OPTIONS Ranges of CPUs are specified with -: 0-2. Default is to trace on all online CPUs. +-v:: +--verbose:: + Increase the verbosity level. + + +OPTIONS for 'perf ftrace trace' +------------------------------- + +-t:: +--tracer=:: + Tracer to use when neither -G nor -F option is not + specified: function_graph or function. + +-F:: +--funcs:: + List available functions to trace. It accepts a pattern to + only list interested functions. + +-D:: +--delay:: + Time (ms) to wait before starting tracing after program start. + -m:: --buffer-size:: Set the size of per-cpu tracing buffer, <size> is expected to @@ -114,6 +124,25 @@ OPTIONS thresh=<n> - Setup trace duration threshold in microseconds. depth=<n> - Set max depth for function graph tracer to follow. + +OPTIONS for 'perf ftrace latency' +--------------------------------- + +-T:: +--trace-funcs=:: + Set the function name to get the histogram. Unlike perf ftrace trace, + it only allows single function to calculate the histogram. + +-b:: +--use-bpf:: + Use BPF to measure function latency instead of using the ftrace (it + uses function_graph tracer internally). + +-n:: +--use-nsec:: + Use nano-second instead of micro-second as a base unit of the histogram. + + SEE ALSO -------- linkperf:perf-record[1], linkperf:perf-trace[1] |