Messages in this thread | | | From | Jiri Olsa <> | Date | Tue, 12 Jul 2022 13:35:25 +0200 | Subject | Re: [PATCH v2 00/14] perf mem/c2c: Add support for AMD |
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On Thu, Jun 16, 2022 at 05:06:23PM +0530, Ravi Bangoria wrote: > Perf mem and c2c tools are wrappers around perf record with mem load/ > store events. IBS tagged load/store sample provides most of the > information needed for these tools. Enable support for these tools on > AMD Zen processors based on IBS Op pmu. > > There are some limitations though: Only load/store instructions provide > mem/c2c information. However, IBS does not provide a way to choose a > particular type of instruction to tag. This results in many non-LS > instructions being tagged which appear as N/A. IBS, being an uncore pmu > from kernel point of view[1], does not support per process monitoring. > Thus, perf mem/c2c on AMD are currently supported in per-cpu mode only. > > Example: > $ sudo ./perf mem record -- -c 10000 > ^C[ perf record: Woken up 227 times to write data ] > [ perf record: Captured and wrote 58.760 MB perf.data (836978 samples) ] > > $ sudo ./perf mem report -F mem,sample,snoop > Samples: 836K of event 'ibs_op//', Event count (approx.): 8418762 > Memory access Samples Snoop > N/A 700620 N/A > L1 hit 126675 N/A > L2 hit 424 N/A > L3 hit 664 HitM > L3 hit 10 N/A > Local RAM hit 2 N/A > Remote RAM (1 hop) hit 8558 N/A > Remote Cache (1 hop) hit 3 N/A > Remote Cache (1 hop) hit 2 HitM > Remote Cache (2 hops) hit 10 HitM > Remote Cache (2 hops) hit 6 N/A > Uncached hit 4 N/A > > Prepared on amd/perf/core (9886142c7a22) + IBS Zen4 enhancement patches[2] > > [1]: https://lore.kernel.org/lkml/20220113134743.1292-1-ravi.bangoria@amd.com > [2]: https://lore.kernel.org/lkml/20220604044519.594-1-ravi.bangoria@amd.com > > v1: https://lore.kernel.org/lkml/20220525093938.4101-1-ravi.bangoria@amd.com > v1->v2: > - Instead of defining macros to extract IBS register bits, use existing > bitfield definitions. Zen4 has introduced additional set of bits in > IBS registers which this series also exploits and thus this series > now depends on IBS Zen4 enhancement patchset. > - Add support for PERF_SAMPLE_WEIGHT_STRUCT. While opening a new event, > perf tool starts with a set of attributes and goes on reverting some > attributes in a predefined order until it succeeds or run out or all > attempts. Here, 1st attempt includes WEIGHT_STRUCT and exclude_guest > which always fails because IBS does not support guest filtering. The > problem however is, perf reverts WEIGHT_STRUCT but keeps trying with > exclude_guest. Thus, although, this series enables WEIGHT_STRUCT > support from kernel, using it from the perf tool need more changes. > I'll try to address this bug later. > - Introduce __PERF_SAMPLE_CALLCHAIN_EARLY to hint generic perf driver > that physical address is set by arch pmu driver and should not be > overwritten. > > > Ravi Bangoria (14): > perf/mem: Introduce PERF_MEM_LVLNUM_{EXTN_MEM|IO} > perf/x86/amd: Add IBS OP_DATA2 DataSrc bit definitions > perf/x86/amd: Support PERF_SAMPLE_DATA_SRC > perf/x86/amd: Support PERF_SAMPLE_{WEIGHT|WEIGHT_STRUCT} > perf/x86/amd: Support PERF_SAMPLE_ADDR > perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR > perf tool: Sync include/uapi/linux/perf_event.h header > perf tool: Sync arch/x86/include/asm/amd-ibs.h header > perf mem: Add support for printing PERF_MEM_LVLNUM_{EXTN_MEM|IO} > perf mem/c2c: Set PERF_SAMPLE_WEIGHT for LOAD_STORE events > perf mem/c2c: Add load store event mappings for AMD > perf mem/c2c: Avoid printing empty lines for unsupported events > perf mem: Use more generic term for LFB > perf script: Add missing fields in usage hint
tools part looks good to me
Acked-by: Jiri Olsa <jolsa@kernel.org>
thanks, jirka
> > arch/x86/events/amd/ibs.c | 372 ++++++++++++++++++++++- > arch/x86/include/asm/amd-ibs.h | 16 + > include/uapi/linux/perf_event.h | 5 +- > kernel/events/core.c | 4 +- > tools/arch/x86/include/asm/amd-ibs.h | 16 + > tools/include/uapi/linux/perf_event.h | 5 +- > tools/perf/Documentation/perf-c2c.txt | 14 +- > tools/perf/Documentation/perf-mem.txt | 3 +- > tools/perf/Documentation/perf-record.txt | 1 + > tools/perf/arch/x86/util/mem-events.c | 31 +- > tools/perf/builtin-c2c.c | 1 + > tools/perf/builtin-mem.c | 1 + > tools/perf/builtin-script.c | 7 +- > tools/perf/util/mem-events.c | 17 +- > 14 files changed, 467 insertions(+), 26 deletions(-) > > -- > 2.31.1 >
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