Messages in this thread | | | From | Ian Rogers <> | Date | Mon, 15 May 2023 15:49:45 -0700 | Subject | Re: [PATCH v4 00/44] Fix perf on Intel hybrid CPUs |
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On Sun, May 14, 2023 at 5:03 AM Liang, Kan <kan.liang@linux.intel.com> wrote: > > > > On 2023-05-12 2:33 p.m., Arnaldo Carvalho de Melo wrote: > > Em Wed, May 03, 2023 at 04:56:36PM -0400, Liang, Kan escreveu: > >> > >> > >> On 2023-05-02 6:38 p.m., Ian Rogers wrote: > >>> TL;DR: hybrid doesn't crash, json metrics work on hybrid on both PMUs > >>> or individually, event parsing doesn't always scan all PMUs, more and > >>> new tests that also run without hybrid, less code. > >>> > >>> The first 4 patches are aimed at Linux 6.4 to address issues raised, > >>> in particular by Kan, on the existing perf stat behavior with json > >>> metrics. They avoid duplicated events by removing groups. They don't > >>> hide events and metrics to make event multiplexing obvious. They avoid > >>> terminating perf when paranoia is higher due to certain events that > >>> always fail. They avoid rearranging events by PMUs when the events > >>> aren't in a group. > >>> > >>> The next 5 patches avoid grouping events for metrics where they could > >>> never succeed and were previously posted as: > >>> "perf vendor events intel: Add xxx metric constraints" > >>> https://lore.kernel.org/all/20230419005423.343862-1-irogers@google.com/ > >>> In general the generated json is coming from: > >>> https://github.com/intel/perfmon/pull/73 > >>> > >>> Next are some general and test improvements. > >>> > >>> Next event parsing is rewritten to not scan all PMUs for the benefit > >>> of raw and legacy cache parsing, instead these are handled by the > >>> lexer and a new term type. This ultimately removes the need for the > >>> event parser for hybrid to be recursive as legacy cache can be just a > >>> term. Tests are re-enabled for events with hyphens, so AMD's > >>> branch-brs event is now parsable. > >>> > >>> The cputype option is made a generic pmu filter flag and is tested > >>> even on non-hybrid systems. > >>> > >>> The final patches address specific json metric issues on hybrid, in > >>> both the json metrics and the metric code. > >>> > >>> The patches add slightly more code than they remove, in areas like > >>> better json metric constraints and tests, but in the core util code, > >>> the removal of hybrid is a net reduction: > >>> 22 files changed, 711 insertions(+), 1016 deletions(-) > >>> > >>> Sample output is contained in the v1 patch set: > >>> https://lore.kernel.org/lkml/bff481ba-e60a-763f-0aa0-3ee53302c480@linux.intel.com/ > >>> > >>> Tested on Tigerlake, Skylake and Alderlake CPUs. > >>> > >>> The v4 patch set: > >>> - rebase, 1 of the Linux 6.4 recommended patches are merged leaving: > >>> 1) perf metric: Change divide by zero and !support events behavior > >>> 2) perf stat: Introduce skippable evsels > >>> 3) perf metric: Json flag to not group events if gathering a metric group > >>> 4) perf parse-events: Don't reorder ungrouped events by pmu > >>> whose diffstat is: > >>> 30 files changed, 326 insertions(+), 33 deletions(-) > >>> but without the vendor event updates (the tend to be large as they > >>> repeat something per architecture per metric) is just: > >>> 10 files changed, 90 insertions(+), 32 deletions(-) > >> > >> I have tested the 4 patches on top of the perf-tools-next branch on both > >> Cascade Lake and Raptor Lake. The result looks good to me. > >> > >> They address the permission error found in the default mode of perf stat > >> on the Cascade Lake. Thanks Ian for the fix. > >> > >> Arnaldo, could you please consider to back port them for the 6.4? > > > > Yes, its in perf-tools now, will go to Linus next week. > > Thanks Arnaldo! > > > > > What about the other patches? I saw some you provided your review, what > > about the others, are you ok with them? > > > > Yes, I'm OK with the patch set. It fixes many issues. Thanks Ian. > (My tests mainly focus on the area in which the patch set may touch. I > did the tests on various platforms, ADL (hybrid), Cascade Lake, SPR.) > > Tested-by: Kan Liang <kan.liang@linux.intel.com> > > But there are still some issues. I don't think they are introduced by > this patch set. We may fix them later separately. > > - Segmentation fault with perf stat --topdown on ADL (hybrid) and > Cascade Lake. > It looks like a legacy issue, may not be introduced by this patch set. > Here is the backtrace. It looks like there is a NULL metric_group. > > (gdb) backtrace > #0 0x00007ffff73035d1 in __strstr_sse2_unaligned () from /lib64/libc.so.6 > #1 0x00000000004f9019 in metricgroup__topdown_max_level_callback > (pm=<optimized out>, table=<optimized out>, > data=0x7fffffff92f4) at util/metricgroup.c:1722 > #2 0x00000000005e8a31 in pmu_metrics_table_for_each_metric > (table=0xcb74d0 <pmu_events_map+368>, > fn=fn@entry=0x4f8ff0 <metricgroup__topdown_max_level_callback>, > data=data@entry=0x7fffffff92f4) > at pmu-events/pmu-events.c:61123 > #3 0x00000000004fbc3b in metricgroups__topdown_max_level () at > util/metricgroup.c:1742 > #4 0x000000000042c135 in add_default_attributes () at builtin-stat.c:1845 > #5 cmd_stat (argc=0, argv=0x7fffffffe3e0) at builtin-stat.c:2446 > #6 0x00000000004b922b in run_builtin (p=p@entry=0xd5c530 > <commands+336>, argc=argc@entry=2, > argv=argv@entry=0x7fffffffe3e0) at perf.c:323 > #7 0x000000000040e373 in handle_internal_command (argv=0x7fffffffe3e0, > argc=2) at perf.c:377 > #8 run_argv (argv=<synthetic pointer>, argcp=<synthetic pointer>) at > perf.c:421 > #9 main (argc=2, argv=0x7fffffffe3e0) at perf.c:537 > (gdb)
Thanks, there's a 1-liner for the segv: https://lore.kernel.org/lkml/20230515224530.671331-1-irogers@google.com/ Arnaldo, can we make sure this goes toward the next 6.4 release candidate?
Thanks, Ian
> Also, the return type is unsigned int, but a bool is given. > > unsigned int metricgroups__topdown_max_level(void) > { > unsigned int max_level = 0; > const struct pmu_metrics_table *table = pmu_metrics_table__find(); > > if (!table) > return false; > > > > - The perf metric and metricgroups fail on different platforms. > Ian and I have discussed it. We agree to address it later separately. > > 102: perf all metricgroups test > ADL (hybrid) > 103: perf all metrics test > ADL (hybrid), Cascade Lake, SPR > > - perf list: The [Kernel PMU event] is missed for all the hardware cache > events. > It impacts both hybrid and non-hybrid platforms. > It's a user-visible change introduced by the patch set. > I don't know if anyone cares whether it's a kernel event or a regular > event. It doesn't bother me. So I'm OK with it. > > cpu: > L1-dcache-loads OR cpu/L1-dcache-loads/ > L1-dcache-load-misses OR cpu/L1-dcache-load-misses/ > L1-dcache-stores OR cpu/L1-dcache-stores/ > L1-icache-load-misses OR cpu/L1-icache-load-misses/ > LLC-loads OR cpu/LLC-loads/ > LLC-load-misses OR cpu/LLC-load-misses/ > LLC-stores OR cpu/LLC-stores/ > LLC-store-misses OR cpu/LLC-store-misses/ > dTLB-loads OR cpu/dTLB-loads/ > dTLB-load-misses OR cpu/dTLB-load-misses/ > dTLB-stores OR cpu/dTLB-stores/ > dTLB-store-misses OR cpu/dTLB-store-misses/ > iTLB-load-misses OR cpu/iTLB-load-misses/ > branch-loads OR cpu/branch-loads/ > branch-load-misses OR cpu/branch-load-misses/ > node-loads OR cpu/node-loads/ > node-load-misses OR cpu/node-load-misses/ > branch-instructions OR cpu/branch-instructions/ [Kernel PMU event] > branch-misses OR cpu/branch-misses/ [Kernel PMU event] > bus-cycles OR cpu/bus-cycles/ [Kernel PMU event] > cache-misses OR cpu/cache-misses/ [Kernel PMU event] > cache-references OR cpu/cache-references/ [Kernel PMU event] > cpu-cycles OR cpu/cpu-cycles/ [Kernel PMU event] > instructions OR cpu/instructions/ [Kernel PMU event] > > > - The --cputype only works for the metric in the default mode. > I can still see the cpu_atom events with --cputype core > It may be something we can improve later. > > # ./perf stat --cputype core sleep 2 > > Performance counter stats for 'sleep 2': > > 0.52 msec task-clock # 0.000 CPUs > utilized > 1 context-switches # 1.939 K/sec > 0 cpu-migrations # 0.000 /sec > 69 page-faults # 133.770 K/sec > 2,569,423 cpu_core/cycles/ # 4.981 G/sec > <not counted> cpu_atom/cycles/ > (0.00%) > 3,287,691 cpu_core/instructions/ # 6.374 G/sec > <not counted> cpu_atom/instructions/ > (0.00%) > 555,848 cpu_core/branches/ # 1.078 G/sec > <not counted> cpu_atom/branches/ > (0.00%) > 8,398 cpu_core/branch-misses/ # 16.281 M/sec > <not counted> cpu_atom/branch-misses/ > (0.00%) > 15,416,538 cpu_core/TOPDOWN.SLOTS/ # 36.1 % > tma_backend_bound > # 23.9 % tma_retiring > # 5.6 % > tma_bad_speculation > # 34.4 % > tma_frontend_bound > 3,687,877 cpu_core/topdown-retiring/ > 846,398 cpu_core/topdown-bad-spec/ > 5,320,217 cpu_core/topdown-fe-bound/ > 5,562,045 cpu_core/topdown-be-bound/ > 14,149 cpu_core/INT_MISC.UOP_DROPPING/ # 27.431 M/sec > > > Thanks, > Kan
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