Messages in this thread | | | From | Yang Shi <> | Date | Mon, 13 Mar 2023 11:15:44 -0700 | Subject | Re: [BUG] perf: No samples found when using kcore + coresight |
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On Mon, Mar 13, 2023 at 5:14 AM Leo Yan <leo.yan@linaro.org> wrote: > > On Thu, Mar 09, 2023 at 10:06:41AM -0800, Yang Shi wrote: > > [...] > > > > I reviewed your shared dump, the bad and good perf data both contain the > > > dummy event with 'text_poke = 1'. Could you confirm the shared dump in > > > your previous email is correct or not? > > > > Oops, sorry. I pasted the wrong log. The good one looks like > > (generated by v5.19): > > > > # captured on : Wed Mar 8 18:02:58 2023 > > # header version : 1 > > # data offset : 408 > > # data size : 22640 > > # feat offset : 23048 > > # hostname : fedora > > # os release : 6.2.0-coresight+ > > # perf version : 5.19.g3d7cb6b04c3f > > # arch : aarch64 > > # nrcpus online : 128 > > # nrcpus avail : 128 > > # cpuid : 0x00000000c00fac30 > > # total memory : 2108862504 kB > > # cmdline : /home/yshi/linux/tools/perf/perf record -e > > cs_etm/@tmc_etf63/k --kcore --per-thread -- taskset --cpu-list 1 uname > > # event : name = cs_etm/@tmc_etf63/k, , id = { 3832 }, type = 9, size > > = 128, { sample_period, sample_freq } = 1, sample_type = > > IP|TID|IDENTIFIER, read_format = ID, d > > isabled = 1, exclude_user = 1, exclude_hv = 1, enable_on_exec = 1, > > sample_id_all = 1, { bp_len, config2 } = 0x12792918 > > # event : name = dummy:u, , id = { 3833 }, type = 1, size = 128, > > config = 0x9, { sample_period, sample_freq } = 1, sample_type = > > IP|TID|IDENTIFIER, read_format = ID, > > disabled = 1, exclude_kernel = 1, exclude_hv = 1, mmap = 1, comm = 1, > > enable_on_exec = 1, task = 1, sample_id_all = 1, exclude_guest = 1, > > mmap2 = 1, comm_exec = 1, > > context_switch = 1, ksymbol = 1, bpf_event = 1 > > # CPU_TOPOLOGY info available, use -I to display > > # NUMA_TOPOLOGY info available, use -I to display > > # pmu mappings: armv8_pmuv3_0 = 8, software = 1, arm_cmn_0 = 10, > > uprobe = 7, cs_etm = 9, breakpoint = 5, tracepoint = 2, arm_cmn_1 = > > 11, kprobe = 6 > > # contains AUX area data (e.g. instruction trace) > > # CACHE info available, use -I to display > > # time of first sample : 18446744073.709551 > > # time of last sample : 18446744073.709551 > > # sample duration : 0.000 ms > > # MEM_TOPOLOGY info available, use -I to display > > # missing features: TRACING_DATA CPUDESC BRANCH_STACK GROUP_DESC STAT > > CLOCKID DIR_FORMAT COMPRESSED CPU_PMU_CAPS CLOCK_DATA HYBRID_TOPOLOGY > > HYBRID_CPU_PMU_CAPS > > Thanks for confirmation. > > Just a quick summary, here we have two issues: > > - With command: > perf record -e cs_etm/@tmc_etf63/k --kcore --per-thread \ > -- taskset --cpu-list 1 uname", > > perf doesn't enable "text poke" attribution.
No, it enables "text poke" and perf fails to decode coresight trace data too. It doesn't matter whether "--kcore" is after or before "-e cs/etm/@tmc_etf63/k".
> > - With command: > perf record -e cs_etm/@tmc_etf63/k --kcore --per-thread \ > -- taskset --cpu-list 1 true (in your previous email), or ... > perf record --kcore -e cs_etm/@tmc_etf63/k --per-thread \ > -- taskset --cpu-list 1 uname (in your shared perf data file), > > perf enables "text poke" attribution, in this case, perf fails to decode > Arm CoreSight trace data.
Yes.
> > [...] > > > > Do you mind to share the bad perf.data file with James and me? > > > > Please check the attachment out. Thanks for looking into this problem. > > Thank you for sharing the data. We will look into it.
Thank you.
> > Leo
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