linux.git/tools/perf/Documentation, branch master

perf tools: Document recent additions to the perf.data file header

2026-06-15T19:54:39+00:00

Add documentation for recently added HEADER_E_MACHINE and
HEADER_CLN_SIZE data to the perf.data file. Also fix a typo
at the end of the header section.

Reviewed-by: Ian Rogers 
Signed-off-by: Thomas Falcon 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Dapeng Mi 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add named_threads workload

2026-06-10T21:55:49+00:00

Add a workload that runs X threads that run a unique function named
"named_threads_thread[x]" which performs a multiplication in a loop for
Y loops. Each thread sets its name to "thread[x]".

This can be used to test that processor trace decoding handles
concurrent threads correctly and the correct symbols and thread names
are assigned to samples.

Signed-off-by: James Clark 
Cc: Amir Ayupov 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Jonathan Corbet 
Cc: Leo Yan 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Paschalis Mpeis 
Cc: Shuah Khan 
Cc: Suzuki Poulouse 
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add deterministic workload

2026-06-10T21:55:48+00:00

Add a workload that does the same thing every time for testing CPU trace
decoding.

Reviewed-by: Leo Yan 
Signed-off-by: James Clark 
Cc: Amir Ayupov 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Jonathan Corbet 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Paschalis Mpeis 
Cc: Shuah Khan 
Cc: Suzuki Poulouse 
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add a workload that forces context switches

2026-06-10T21:55:48+00:00

This workload launches two processes that block when reading and writing
to each other forcing the other process to be scheduled for each
read/write pair.

Signed-off-by: James Clark 
Cc: Amir Ayupov 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Jonathan Corbet 
Cc: Leo Yan 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Paschalis Mpeis 
Cc: Shuah Khan 
Cc: Suzuki Poulouse 
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add workload-ctl option

2026-06-10T21:55:48+00:00

Add a --workload-ctl=fifo:ctl-fifo[,ack-fifo] option for 'perf test
-w'. When set, run_workload() opens the named FIFO, writes enable before
invoking the builtin workload, writes disable before returning, and
waits for ack responses when an ack FIFO is provided to ensure that the
workload doesn't run until the events are enabled.

This can be used to limit the scope of the recording to only the
workload execution and avoid recording Perf setup and teardown code if
Perf record is started with events disabled (-D 1).

Assisted-by: Codex:GPT-5.5
Signed-off-by: James Clark 
Cc: Amir Ayupov 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Jonathan Corbet 
Cc: Leo Yan 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Paschalis Mpeis 
Cc: Shuah Khan 
Cc: Suzuki Poulouse 
Signed-off-by: Arnaldo Carvalho de Melo

perf doc: Document new IBS capabilities in man page

2026-05-23T00:32:28+00:00

Include examples of:

o Privilege filter with Fetch and Op PMUs, including swfilt approach on
  Zen5 and older platforms and hardware assisted filter on Zen6 and newer
  platforms

o Streaming store filter with Op PMU

o Fetch latency filter with Fetch PMU

Signed-off-by: Ravi Bangoria 
Acked-by: Namhyung Kim 
Cc: Ananth Narayan 
Cc: Dapeng Mi 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Manali Shukla 
Cc: Peter Zijlstra 
Cc: Sandipan Das 
Cc: Santosh Shukla 
Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Introduce --show-cpu option to display cpu id

2026-05-16T17:38:22+00:00

When tracing system-wide workloads or specific events, it is highly
valuable to know exactly which CPU executed a specific event. Currently,
perf trace output defaults to omitting CPU information.

Introduce a new "--show-cpu" command-line option. When provided, this
flag extracts the CPU from the perf sample and prints it in a "[000]"
format immediately following the timestamp. This mirrors the behaviour of
other tracing tools like ftrace and perf script. For example:

  # perf trace -e sched:sched_switch --max-events 5 --show-cpu
       0.000 [002] :0/0 sched:sched_switch(prev_comm: "swapper/2", prev_prio: 120, next_comm: "rcu_preempt", next_pid: 16 (rcu_preempt), next_prio: 120)
       0.009 [002] rcu_preempt/16 sched:sched_switch(prev_comm: "rcu_preempt", prev_pid: 16 (rcu_preempt), prev_prio: 120, prev_state: 128, next_comm: "swapper/2", next_prio: 120)
       0.033 [002] :0/0 sched:sched_switch(prev_comm: "swapper/2", prev_prio: 120, next_comm: "kworker/u32:48", next_pid: 35840 (kworker/u32:48-), next_prio: 120)
       0.041 [002] kworker/u32:48/35840 sched:sched_switch(prev_comm: "kworker/u32:48", prev_pid: 35840 (kworker/u32:48-), prev_prio: 120, prev_state: 128, next_comm: "swapper/2", next_prio: 120)
       0.045 [002] :0/0 sched:sched_switch(prev_comm: "swapper/2", prev_prio: 120, next_comm: "kworker/u32:48", next_pid: 35840 (kworker/u32:48-), next_prio: 120)

The feature is implemented strictly as an opt-in toggle to prevent
cluttering the standard output and to preserve backwards compatibility
for scripts parsing the default output format.

Signed-off-by: Aaron Tomlin 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Daniel Vacek 
Cc: Howard Chu 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Sean Ashe 
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Update document for SIMD flags

2026-04-10T16:52:06+00:00

Update SIMD architecture and predicate flags.

Reviewed-by: James Clark 
Reviewed-by: Ian Rogers 
Signed-off-by: Leo Yan 
Signed-off-by: Namhyung Kim

perf config: Make symbol_conf::addr2line_disable_warn configurable

2026-04-08T17:28:49+00:00

Make symbol_conf::addr2line_disable_warn configurable by reading
the perfconfig file.
Use section core and addr2line-disable-warn = value.
Update documentation.

Example:
 # perf config -l
 core.addr2line-timeout=5000
 core.addr2line-disable-warn=1
 #

Signed-off-by: Thomas Richter 
Reviewed-by: Ian Rogers 
Suggested-by: Namhyung Kim 
Signed-off-by: Namhyung Kim

perf tools: Add --pmu-filter option for filtering PMUs

2026-03-27T20:58:01+00:00

This patch adds a new --pmu-filter option to perf-stat command to allow
filtering events on specific PMUs. This is useful when there are
multiple PMUs with same type (e.g. hisi_sicl2_cpa0 and hisi_sicl0_cpa0).

[root@localhost tmp]# perf stat -M cpa_p0_avg_bw
 Performance counter stats for 'system wide':

    19,417,779,115      hisi_sicl0_cpa0/cpa_cycles/      #     0.00 cpa_p0_avg_bw
                 0      hisi_sicl0_cpa0/cpa_p0_wr_dat/
                 0      hisi_sicl0_cpa0/cpa_p0_rd_dat_64b/
                 0      hisi_sicl0_cpa0/cpa_p0_rd_dat_32b/
    19,417,751,103      hisi_sicl10_cpa0/cpa_cycles/     #     0.00 cpa_p0_avg_bw
                 0      hisi_sicl10_cpa0/cpa_p0_wr_dat/
                 0      hisi_sicl10_cpa0/cpa_p0_rd_dat_64b/
                 0      hisi_sicl10_cpa0/cpa_p0_rd_dat_32b/
    19,417,730,679      hisi_sicl2_cpa0/cpa_cycles/      #     0.31 cpa_p0_avg_bw
        75,635,749      hisi_sicl2_cpa0/cpa_p0_wr_dat/
        18,520,640      hisi_sicl2_cpa0/cpa_p0_rd_dat_64b/
                 0      hisi_sicl2_cpa0/cpa_p0_rd_dat_32b/
    19,417,674,227      hisi_sicl8_cpa0/cpa_cycles/      #     0.00 cpa_p0_avg_bw
                 0      hisi_sicl8_cpa0/cpa_p0_wr_dat/
                 0      hisi_sicl8_cpa0/cpa_p0_rd_dat_64b/
                 0      hisi_sicl8_cpa0/cpa_p0_rd_dat_32b/

      19.417734480 seconds time elapsed

[root@localhost tmp]# perf stat --pmu-filter hisi_sicl2_cpa0 -M cpa_p0_avg_bw
 Performance counter stats for 'system wide':

     6,234,093,559      cpa_cycles                       #     0.60 cpa_p0_avg_bw
        50,548,465      cpa_p0_wr_dat
         7,552,182      cpa_p0_rd_dat_64b
                 0      cpa_p0_rd_dat_32b

       6.234139320 seconds time elapsed

Signed-off-by: Qinxin Xia 
Reviewed-by: Ian Rogers 
Signed-off-by: Namhyung Kim