[GIT PULL] perf tools changes for v6.19
Perf event/metric description
-----------------------------
Unify all event and metric descriptions in JSON format.
Now event parsing and handling is greatly simplified by that.
From users point of view, perf list will provide richer
information about hardware events like the following.
$ perf list hw
List of pre-defined events (to be used in -e or -M):
legacy hardware:
branch-instructions
[Retired branch instructions [This event is an alias of branches]. Unit: cpu]
branch-misses
[Mispredicted branch instructions. Unit: cpu]
branches
[Retired branch instructions [This event is an alias of branch-instructions]. Unit: cpu]
bus-cycles
[Bus cycles,which can be different from total cycles. Unit: cpu]
cache-misses
[Cache misses. Usually this indicates Last Level Cache misses; this is intended to be used in conjunction with the
PERF_COUNT_HW_CACHE_REFERENCES event to calculate cache miss rates. Unit: cpu]
cache-references
[Cache accesses. Usually this indicates Last Level Cache accesses but this may vary depending on your CPU. This may include
prefetches and coherency messages; again this depends on the design of your CPU. Unit: cpu]
cpu-cycles
[Total cycles. Be wary of what happens during CPU frequency scaling [This event is an alias of cycles]. Unit: cpu]
cycles
[Total cycles. Be wary of what happens during CPU frequency scaling [This event is an alias of cpu-cycles]. Unit: cpu]
instructions
[Retired instructions. Be careful,these can be affected by various issues,most notably hardware interrupt counts. Unit: cpu]
ref-cycles
[Total cycles; not affected by CPU frequency scaling. Unit: cpu]
But most notable changes would be in the perf stat. On the right side,
the default metrics are better named and aligned. :)
$ perf stat -- perf test -w noploop
Performance counter stats for 'perf test -w noploop':
11 context-switches # 10.8 cs/sec cs_per_second
0 cpu-migrations # 0.0 migrations/sec migrations_per_second
3,612 page-faults # 3532.5 faults/sec page_faults_per_second
1,022.51 msec task-clock # 1.0 CPUs CPUs_utilized
110,466 branch-misses # 0.0 % branch_miss_rate (88.66%)
6,934,452,104 branches # 6781.8 M/sec branch_frequency (88.66%)
4,657,032,590 cpu-cycles # 4.6 GHz cycles_frequency (88.65%)
27,755,874,218 instructions # 6.0 instructions insn_per_cycle (89.03%)
TopdownL1 # 0.3 % tma_backend_bound
# 9.3 % tma_bad_speculation (89.05%)
# 9.7 % tma_frontend_bound (77.86%)
# 80.7 % tma_retiring (88.81%)
1.025318171 seconds time elapsed
1.013248000 seconds user
0.012014000 seconds sys
Deferred unwinding support
--------------------------
With the kernel support [1], perf can use deferred callchains for
userspace stack trace with frame pointers like below:
$ perf record --call-graph fp,defer ...
This will be transparent to users when it comes to other commands like
perf report and perf script. They will merge the deferred callchains to
the previous samples as if they were collected together.
[1] https://git.kernel.org/torvalds/c/c69993ecdd4dfde2b7da08b022052a33b203da07
ARM SPE updates
---------------
* Extensive enhancements to support various kinds of memory operations
including GCS, MTE allocation tags, memcpy/memset, register access,
and SIMD operations.
* Add inverted data source filter (inv_data_src_filter) support to
exclude certain data sources.
* Improve documentation.
Vendor event updates
--------------------
* Intel: Updated event files for Sierra Forest, Panther Lake, Meteor Lake,
Lunar Lake, Granite Rapids, and others.
* Arm64: Added metrics for i.MX94 DDR PMU and Cortex-A720AE definitions.
* RISC-V: Added JSON support for T-HEAD C920V2.
Misc
----
* Improve pointer tracking in data type profiling. It'd give better
output when the variable is using container_of() to convert type.
* Annotation support for perf c2c report in TUI. Press 'a' key to
enter annotation view from cacheline browser window. This will show
which instruction is causing the cacheline contention.
* Lots of fixes and test coverage improvements!
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
libperf: Use 'extern' in LIBPERF_API visibility macro
Use 'extern' on LIBPERF_API to address this issue that started appearing
with gcc 15, first seen in ubuntu 25.10:
evlist.c: In function 'perf_evlist__purge':
evlist.c:202:17: error: implicit declaration of function 'perf_evsel__delete'; did you mean 'perf_evsel__exit'? [-Wimplicit-function-declaration]
202 | perf_evsel__delete(pos);
| ^~~~~~~~~~~~~~~~~~
| perf_evsel__exit
evlist.c:202:17: error: nested extern declaration of 'perf_evsel__delete' [-Werror=nested-externs]
evlist.c: In function 'perf_evlist__open':
evlist.c:261:23: error: implicit declaration of function 'perf_evsel__open'; did you mean 'perf_evsel__exit'? [-Wimplicit-function-declaration]
261 | err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
| ^~~~~~~~~~~~~~~~
| perf_evsel__exit
evlist.c:261:23: error: nested extern declaration of 'perf_evsel__open' [-Werror=nested-externs]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
1 file changed
