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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-27 13:42:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-27 13:42:32 -0700
commit7b58b82b86c8b65a2b57a4c6cb96a460654f9e09 (patch)
treea13e19f216389f16f1cb6641d54751f167482515 /tools/perf/Documentation/perf-ftrace.txt
parentMerge tag 'memblock-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock (diff)
parentperf evsel: Improve AMD IBS (Instruction-Based Sampling) error handling messages (diff)
downloadlinux-dev-7b58b82b86c8b65a2b57a4c6cb96a460654f9e09.tar.xz
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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.txt75
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]