'perf top' broken on intel hybrid systems
From: Arnaldo Carvalho de Melo
Date: Fri Dec 08 2023 - 13:59:47 EST
Hi,
So I finally got a recent Intel hybrid system:
root@fedora:~# grep -m1 "model name" /proc/cpuinfo
model name : Intel(R) Core(TM) i7-14700K
root@fedora:~#
Most things work, but:
root@fedora:~# perf top
Error:
The cycles:P event is not supported.
root@fedora:~#
root@fedora:~# perf top -e cycles:p
Error:
The cycles:p event is not supported.
root@fedora:~# perf top -e cycles:pp
Error:
The cycles:pp event is not supported.
^[[Aroot@fedora:~# perf top -e cycles:ppp
Error:
The cycles:ppp event is not supported.
root@fedora:~#
root@fedora:~# perf top -e cycles
Error:
The cycles event is not supported.
root@fedora:~#
root@fedora:~# perf top -e instructions
Error:
The instructions event is not supported.
root@fedora:~#root@fedora:~# perf top -e cache-misses
Error:
The cache-misses event is not supported.
root@fedora:~#
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
size 136
config 0xa00000000
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|ID|CPU|PERIOD
read_format ID|LOST
disabled 1
inherit 1
mmap 1
comm 1
freq 1
task 1
sample_id_all 1
exclude_guest 1
mmap2 1
comm_exec 1
ksymbol 1
bpf_event 1
------------------------------------------------------------
sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8
sys_perf_event_open failed, error -2
Error:
The cycles event is not supported.
root@fedora:~#
But...
root@fedora:~# perf record
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.631 MB perf.data (24079 samples) ]
root@fedora:~# perf evlist -v
cpu_atom/cycles:P/: type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0xa00000000, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|IDENTIFIER, read_format: ID|LOST, disabled: 1, inherit: 1, freq: 1, precise_ip: 3, sample_id_all: 1
cpu_core/cycles:P/: type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0x400000000, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|IDENTIFIER, read_format: ID|LOST, disabled: 1, inherit: 1, freq: 1, precise_ip: 3, sample_id_all: 1
dummy:u: type: 1 (PERF_TYPE_SOFTWARE), size: 136, config: 0x9 (PERF_COUNT_SW_DUMMY), { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|IDENTIFIER, read_format: ID|LOST, inherit: 1, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
root@fedora:~#
root@fedora:~# perf top -e cpu_core/cpu-cycles:P/
event syntax error: 'cpu_core/cpu-cycles:P/'
\___ Bad event or PMU
Unable to find PMU or event on a PMU of 'cpu_core'
Initial error:
event syntax error: 'cpu_core/cpu-cycles:P/'
\___ unknown term 'cpu-cycles:P' for pmu 'cpu_core'
valid terms: event,pc,edge,offcore_rsp,ldlat,inv,umask,frontend,cmask,config,config1,config2,config3,name,period,freq,branch_type,time,call-graph,stack-size,no-inherit,inherit,max-stack,nr,no-overwrite,overwrite,driver-config,percore,aux-output,aux-sample-size,metric-id,raw,legacy-cache,hardware
Run 'perf list' for a list of valid events
Usage: perf top [<options>]
-e, --event <event> event selector. use 'perf list' to list available events
root@fedora:~#
So it seems its just 'perf top' breakage:
root@fedora:~# perf top -e cpu_core/cpu-cycles/
Error:
The cpu_core/cpu-cycles/ event is not supported.
root@fedora:~# perf top -e cpu_atom/cpu-cycles/
Error:
The cpu_atom/cpu-cycles/ event is not supported.
root@fedora:~#
I bisected this to:
⬢[acme@toolbox perf-tools-next]$ git bisect good
251aa040244a3b17068e4e6ec61f138d7e50681a is the first bad commit
commit 251aa040244a3b17068e4e6ec61f138d7e50681a
Author: Ian Rogers <irogers@xxxxxxxxxx>
Date: Thu Jun 1 01:29:53 2023 -0700
perf parse-events: Wildcard most "numeric" events
Numeric events are either raw events or those with ABI defined numbers
matched by the lexer. PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE events
should wildcard match on hybrid systems. So "cycles" should match each
PMU type with an extended type, not just PERF_TYPE_HARDWARE.
Change wildcard matching to add the event even if wildcard PMU
scanning fails, there will be no extended type but this best matches
previous behavior.
Only set the extended type when the event type supports it and when
perf_pmus__supports_extended_type is true. This new function returns
true if >1 core PMU and avoids potential errors on older kernels.
Modify evsel__compute_group_pmu_name using a helper
perf_pmu__is_software to determine when grouping should occur. Try to
use PMUs, and evsel__find_pmu, as being more dependable than
evsel->pmu_name.
Set a parse events error if a hardware term's PMU lookup fails, to
provide extra diagnostics.
Fixes: 8bc75f699c141420 ("perf parse-events: Support wildcards on raw events")
Reported-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Tested-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ravi Bangoria <ravi.bangoria@xxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Cc: Xing Zhengjun <zhengjun.xing@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230601082954.754318-4-irogers@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
tools/perf/util/parse-events.c | 104 +++++++++++++++++++++++++++++------------
tools/perf/util/parse-events.y | 10 ++--
tools/perf/util/pmu.c | 16 +++++++
tools/perf/util/pmu.h | 5 ++
tools/perf/util/pmus.c | 5 ++
tools/perf/util/pmus.h | 1 +
6 files changed, 106 insertions(+), 35 deletions(-)
⬢[acme@toolbox perf-tools-next]$
- Arnaldo