The 'perf mem' and 'perf 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. Wire in the "ibs_op//" event
as mem-ldst event for AMD.
There are some limitations though: Only load/store micro-ops provide
mem/c2c information. Whereas, IBS does not have a way to choose a
particular type of micro-op to tag. This results in many non-LS
micro-ops being tagged which appear as N/A in the perf report. 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
$
[1]: https://lore.kernel.org/lkml/20220829113347.295-1-ravi.bangoria@amd.com
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ali Saidi <alisaidi@amazon.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: https://lore.kernel.org/r/20221006153946.7816-6-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For enabling mem-store event, it doesn't need an auxiliary event.
So just build an event name string with the pmu prefix.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210527001610.10553-4-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf_mem_events__name() can generate the mem-load event name.
It uses a variable 'mem_loads_name__init' to avoid generating the
event name every time (because perf_pmu__scan takes some time).
The perf_mem_events__name() assumes the pmu is "cpu" but it's not
correct for hybrid platform. For Alderlake, the pmu is "cpu_core" or
"cpu_atom"
Introduce a new parameter 'pmu_name' in perf_mem_events__name
to let the caller specify a pmu name.
Considering such event name is x86 specific, so move
perf_mem_events[] to arch/x86/util/mem-events.c.
We still keep the variable 'mem_loads_name__init' but it's only
used when pmu_name is NULL (compatible for original behavior). When
pmu_name is not NULL (e.g. "cpu_core"), this patch doesn't have
optimization. That can be implemented in follow up patch.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210527001610.10553-3-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For some platforms, an auxiliary event has to be enabled
simultaneously with the load latency event.
For Alderlake, the auxiliary event is created in "cpu_core" pmu.
So first we need to check the existing of "cpu_core" pmu
and then check if this pmu has auxiliary event.
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210527001610.10553-2-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
On the Intel Sapphire Rapids server, an auxiliary event has to be
enabled simultaneously with the load latency event to retrieve complete
Memory Info.
Add X86 specific perf_mem_events__name() to handle the auxiliary event.
- Users are only interested in the samples of the mem-loads event.
Sample read the auxiliary event.
- The auxiliary event must be in front of the load latency event in a
group. Assume the second event to sample if the auxiliary event is the
leader.
- Add a weak is_mem_loads_aux_event() to check the auxiliary event for
X86. For other ARCHs, it always return false.
Parse the unique event name, mem-loads-aux, for the auxiliary event.
Committer notes:
According to 61b985e3e7 ("perf/x86/intel: Add perf core PMU
support for Sapphire Rapids"), ENODATA is only returned by
sys_perf_event_open() when used with these auxiliary events, with this
in evsel__open_strerror():
case ENODATA:
return scnprintf(msg, size, "Cannot collect data source with the load latency event alone. "
"Please add an auxiliary event in front of the load latency event.");
This is Ok at this point in time, but fragile long term, I pointed this
out in the e-mail thread, requesting a follow up patch to check if
ENODATA is really for this specific case.
Fixed up sizeof(MEM_LOADS_AUX_NAME) bug pointed out by Namhyung.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210205152648.GC920417@kernel.org
Link: http://lore.kernel.org/lkml/1612296553-21962-3-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
