The default config is computed during creation of the PMU and may do
things like scanning sysfs, when the PMU may just be used as part of
scanning. Change default_config to perf_event_attr_init_default, a
callback that is used when a default config needs initializing. This
avoids holding onto the memory for a perf_event_attr and copying.
On a tigerlake laptop running the pmu-scan benchmark:
Before:
Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 100 times
Average core PMU scanning took: 28.780 usec (+- 0.503 usec)
Average PMU scanning took: 283.480 usec (+- 18.471 usec)
Number of openat syscalls: 30,227
After:
Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 100 times
Average core PMU scanning took: 27.880 usec (+- 0.169 usec)
Average PMU scanning took: 245.260 usec (+- 15.758 usec)
Number of openat syscalls: 28,914
Over 3 runs it is a nearly 12% reduction in execution time and a 4.3%
of openat calls.
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Will Deacon <will@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20231012175645.1849503-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
'perf record' and 'perf report --dump-raw-trace' supported in this
release.
Example usage:
# perf record -e arm_spe/ts_enable=1,pa_enable=1/ dd if=/dev/zero of=/dev/null count=10000
# perf report --dump-raw-trace
Note that the perf.data file is portable, so the report can be run on
another architecture host if necessary.
Output will contain raw SPE data and its textual representation, such
as:
0x5c8 [0x30]: PERF_RECORD_AUXTRACE size: 0x200000 offset: 0 ref: 0x1891ad0e idx: 1 tid: 2227 cpu: 1
.
. ... ARM SPE data: size 2097152 bytes
. 00000000: 49 00 LD
. 00000002: b2 c0 3b 29 0f 00 00 ff ff VA 0xffff00000f293bc0
. 0000000b: b3 c0 eb 24 fb 00 00 00 80 PA 0xfb24ebc0 ns=1
. 00000014: 9a 00 00 LAT 0 XLAT
. 00000017: 42 16 EV RETIRED L1D-ACCESS TLB-ACCESS
. 00000019: b0 00 c4 15 08 00 00 ff ff PC 0xff00000815c400 el3 ns=1
. 00000022: 98 00 00 LAT 0 TOT
. 00000025: 71 36 6c 21 2c 09 00 00 00 TS 39395093558
. 0000002e: 49 00 LD
. 00000030: b2 80 3c 29 0f 00 00 ff ff VA 0xffff00000f293c80
. 00000039: b3 80 ec 24 fb 00 00 00 80 PA 0xfb24ec80 ns=1
. 00000042: 9a 00 00 LAT 0 XLAT
. 00000045: 42 16 EV RETIRED L1D-ACCESS TLB-ACCESS
. 00000047: b0 f4 11 16 08 00 00 ff ff PC 0xff0000081611f4 el3 ns=1
. 00000050: 98 00 00 LAT 0 TOT
. 00000053: 71 36 6c 21 2c 09 00 00 00 TS 39395093558
. 0000005c: 48 00 INSN-OTHER
. 0000005e: 42 02 EV RETIRED
. 00000060: b0 2c ef 7f 08 00 00 ff ff PC 0xff0000087fef2c el3 ns=1
. 00000069: 98 00 00 LAT 0 TOT
. 0000006c: 71 d1 6f 21 2c 09 00 00 00 TS 39395094481
...
Other release notes:
- applies to acme's perf/{core,urgent} branches, likely elsewhere
- Report is self-contained within the tool.
Record requires enabling the kernel SPE driver by
setting CONFIG_ARM_SPE_PMU.
- The intel-bts implementation was used as a starting point; its
min/default/max buffer sizes and power of 2 pages granularity need to be
revisited for ARM SPE
- Recording across multiple SPE clusters/domains not supported
- Snapshot support (record -S), and conversion to native perf events
(e.g., via 'perf inject --itrace'), are also not supported
- Technically both cs-etm and spe can be used simultaneously, however
disabled for simplicity in this release
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Reviewed-by: Dongjiu Geng <gengdongjiu@huawei.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180114132850.0b127434b704a26bad13268f@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers
Kim Phillips