linux/tools/perf/arch
Kan Liang 2a57d40832 perf tools: Support the auxiliary event
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>
2021-02-08 16:25:00 -03:00
..
alpha perf tools: Add empty Build files for architectures lacking them 2015-08-06 16:24:15 -03:00
arc/annotate perf annotate: Introduce basic support for ARC 2018-12-17 14:59:42 -03:00
arm perf evlist: Use the right prefix for 'struct evlist' evsel list methods 2020-11-30 14:52:44 -03:00
arm64 perf arm64: Add argument support for SDT 2020-12-28 09:53:28 -03:00
csky perf tools: Avoid 'sample_reg_masks' being const + weak 2019-10-10 09:29:33 -03:00
mips perf annotate mips: Add perf arch instructions annotate handlers 2020-11-04 09:42:40 -03:00
nds32 perf tools: Rename build libperf to perf 2019-02-14 15:18:08 -03:00
parisc perf tools: Add empty Build files for architectures lacking them 2015-08-06 16:24:15 -03:00
powerpc perf powerpc: Support exposing Performance Monitor Counter SPRs as part of extended regs 2021-02-08 16:25:00 -03:00
riscv perf tools: Avoid 'sample_reg_masks' being const + weak 2019-10-10 09:29:33 -03:00
s390 perf tools: Update s390's syscall.tbl copy from the kernel sources 2020-12-24 09:24:20 -03:00
sh treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
sparc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
x86 perf tools: Support the auxiliary event 2021-02-08 16:25:00 -03:00
xtensa treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
Build perf tools: Rename build libperf to perf 2019-02-14 15:18:08 -03:00
common.c perf debug: Remove needless include directives from debug.h 2019-08-31 19:10:19 -03:00
common.h perf env: Remove env.h from other headers where just a fwd decl is needed 2019-08-31 19:10:40 -03:00