Commit b2ad9549 authored by Ravi Bangoria's avatar Ravi Bangoria Committed by Namhyung Kim
Browse files

perf evsel amd: Fix IBS error message 

AMD IBS can do per-process profiling[1] and is no longer restricted to
per-cpu or systemwide only. Remove stale error message. Also, checking
just exclude_kernel is not sufficient since IBS does not support any
privilege filters. So include all exclude_* checks. And finally, move
these checks under tools/perf/arch/x86/ from generic code.

Before:
  $ sudo ./perf record -e ibs_op//k -C 0
  Error:
  AMD IBS may only be available in system-wide/per-cpu mode.  Try
  using -a, or -C and workload affinity

After:
  $ sudo ./perf record -e ibs_op//k -C 0
  Error:
  AMD IBS doesn't support privilege filtering. Try again without
  the privilege modifiers (like 'k') at the end.

[1] https://git.kernel.org/torvalds/c/30093056f7b2



Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@amd.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: ananth.narayan@amd.com
Cc: sandipan.das@amd.com
Cc: santosh.shukla@amd.com
Cc: irogers@google.com
Cc: peterz@infradead.org
Cc: adrian.hunter@intel.com
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: https://lore.kernel.org/r/20230630085230.437-1-ravi.bangoria@amd.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent 5f06267b

tools/perf/arch/x86/util/evsel.c

+20 −0
Original line number Diff line number Diff line
@@ -102,3 +102,23 @@ void arch__post_evsel_config(struct evsel *evsel, struct perf_event_attr *attr) 
		}

	}

}



int arch_evsel__open_strerror(struct evsel *evsel, char *msg, size_t size)

{

	if (!x86__is_amd_cpu())

		return 0;



	if (!evsel->core.attr.precise_ip &&

	    !(evsel->pmu_name && !strncmp(evsel->pmu_name, "ibs", 3)))

		return 0;



	/* More verbose IBS errors. */

	if (evsel->core.attr.exclude_kernel || evsel->core.attr.exclude_user ||

	    evsel->core.attr.exclude_hv || evsel->core.attr.exclude_idle ||

	    evsel->core.attr.exclude_host || evsel->core.attr.exclude_guest) {

		return scnprintf(msg, size, "AMD IBS doesn't support privilege filtering. Try "

				 "again without the privilege modifiers (like 'k') at the end.");

	}



	return 0;

}

tools/perf/util/evsel.c

+9 −21
Original line number Diff line number Diff line
@@ -2924,25 +2924,19 @@ static bool find_process(const char *name) 
	return ret ? false : true;

}



static bool is_amd(const char *arch, const char *cpuid)

int __weak arch_evsel__open_strerror(struct evsel *evsel __maybe_unused,

				     char *msg __maybe_unused,

				     size_t size __maybe_unused)

{

	return arch && !strcmp("x86", arch) && cpuid && strstarts(cpuid, "AuthenticAMD");

}



static bool is_amd_ibs(struct evsel *evsel)

{

	return evsel->core.attr.precise_ip

	    || (evsel->pmu_name && !strncmp(evsel->pmu_name, "ibs", 3));

	return 0;

}



int evsel__open_strerror(struct evsel *evsel, struct target *target,

			 int err, char *msg, size_t size)

{

	struct perf_env *env = evsel__env(evsel);

	const char *arch = perf_env__arch(env);

	const char *cpuid = perf_env__cpuid(env);

	char sbuf[STRERR_BUFSIZE];

	int printed = 0, enforced = 0;

	int ret;



	switch (err) {

	case EPERM:
@@ -3044,16 +3038,6 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target, 
			return scnprintf(msg, size,

	"Invalid event (%s) in per-thread mode, enable system wide with '-a'.",

					evsel__name(evsel));

		if (is_amd(arch, cpuid)) {

			if (is_amd_ibs(evsel)) {

				if (evsel->core.attr.exclude_kernel)

					return scnprintf(msg, size,

	"AMD IBS can't exclude kernel events.  Try running at a higher privilege level.");

				if (!evsel->core.system_wide)

					return scnprintf(msg, size,

	"AMD IBS may only be available in system-wide/per-cpu mode.  Try using -a, or -C and workload affinity");

			}

		}



		break;

	case ENODATA:
@@ -3063,6 +3047,10 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target, 
		break;

	}



	ret = arch_evsel__open_strerror(evsel, msg, size);

	if (ret)

		return ret;



	return scnprintf(msg, size,

	"The sys_perf_event_open() syscall returned with %d (%s) for event (%s).\n"

	"/bin/dmesg | grep -i perf may provide additional information.\n",

tools/perf/util/evsel.h

+1 −0
Original line number Diff line number Diff line
@@ -311,6 +311,7 @@ void evsel__set_sample_id(struct evsel *evsel, bool use_sample_identifier); 


void arch_evsel__set_sample_weight(struct evsel *evsel);

void arch__post_evsel_config(struct evsel *evsel, struct perf_event_attr *attr);

int arch_evsel__open_strerror(struct evsel *evsel, char *msg, size_t size);



int evsel__set_filter(struct evsel *evsel, const char *filter);

int evsel__append_tp_filter(struct evsel *evsel, const char *filter);