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 with
exclude_{kernel|user|hv|idle|host|guest}=0.
Signed-off-by: Ravi Bangoria <[email protected]>
---
v1: https://lore.kernel.org/r/[email protected]
v1->v2:
- Check all exclude_* flags not just exclude_kernel
- Move AMD specific checks under tools/perf/arch/x86/
tools/perf/arch/x86/util/evsel.c | 25 +++++++++++++++++++++++++
tools/perf/util/evsel.c | 30 +++++++++---------------------
tools/perf/util/evsel.h | 1 +
3 files changed, 35 insertions(+), 21 deletions(-)
diff --git a/tools/perf/arch/x86/util/evsel.c b/tools/perf/arch/x86/util/evsel.c
index 512c2d885d24..9a7141c5a4ea 100644
--- a/tools/perf/arch/x86/util/evsel.c
+++ b/tools/perf/arch/x86/util/evsel.c
@@ -102,3 +102,28 @@ 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 with exclude_{kernel|user|hv|idle|host|guest}=0.");
+ }
+
+ if (!evsel->core.attr.sample_period) {
+ return scnprintf(msg, size, "AMD IBS doesn't support counting mode. Try "
+ "again with sample_{period|freq} with non-zero value.");
+ }
+
+ return 0;
+}
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index f607b5bddc76..762e2b2634a5 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -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",
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 9f06d6cd5379..848534ec74fa 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -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);
--
2.41.0
On 26-Jun-23 4:09 PM, Ravi Bangoria wrote:
> 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 with
> exclude_{kernel|user|hv|idle|host|guest}=0.
[1] https://git.kernel.org/torvalds/c/30093056f7b2
Hi Ravi,
On Mon, Jun 26, 2023 at 3:40 AM Ravi Bangoria <[email protected]> wrote:
>
> 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 with
> exclude_{kernel|user|hv|idle|host|guest}=0.
Can we have more user-friendly messages like below?
"Try again without the privilege modifiers like 'k' at the end."
>
> Signed-off-by: Ravi Bangoria <[email protected]>
> ---
> v1: https://lore.kernel.org/r/[email protected]
> v1->v2:
> - Check all exclude_* flags not just exclude_kernel
> - Move AMD specific checks under tools/perf/arch/x86/
>
> tools/perf/arch/x86/util/evsel.c | 25 +++++++++++++++++++++++++
> tools/perf/util/evsel.c | 30 +++++++++---------------------
> tools/perf/util/evsel.h | 1 +
> 3 files changed, 35 insertions(+), 21 deletions(-)
>
> diff --git a/tools/perf/arch/x86/util/evsel.c b/tools/perf/arch/x86/util/evsel.c
> index 512c2d885d24..9a7141c5a4ea 100644
> --- a/tools/perf/arch/x86/util/evsel.c
> +++ b/tools/perf/arch/x86/util/evsel.c
> @@ -102,3 +102,28 @@ 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 with exclude_{kernel|user|hv|idle|host|guest}=0.");
> + }
> +
> + if (!evsel->core.attr.sample_period) {
> + return scnprintf(msg, size, "AMD IBS doesn't support counting mode. Try "
> + "again with sample_{period|freq} with non-zero value.");
Is this for perf stat? We don't allow zero period for perf record.
$ perf record -F 0 true
frequency and count are zero, aborting
Then maybe it can say: "IBS doesn't support perf stat, Use perf record."
Thanks,
Namhyung
> + }
> +
> + return 0;
> +}
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index f607b5bddc76..762e2b2634a5 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -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",
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 9f06d6cd5379..848534ec74fa 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -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);
> --
> 2.41.0
>
On 27-Jun-23 4:34 AM, Namhyung Kim wrote:
> Hi Ravi,
>
> On Mon, Jun 26, 2023 at 3:40 AM Ravi Bangoria <[email protected]> wrote:
>>
>> 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 with
>> exclude_{kernel|user|hv|idle|host|guest}=0.
>
> Can we have more user-friendly messages like below?
>
> "Try again without the privilege modifiers like 'k' at the end."
Sure.
>
>>
>> Signed-off-by: Ravi Bangoria <[email protected]>
>> ---
>> v1: https://lore.kernel.org/r/[email protected]
>> v1->v2:
>> - Check all exclude_* flags not just exclude_kernel
>> - Move AMD specific checks under tools/perf/arch/x86/
>>
>> tools/perf/arch/x86/util/evsel.c | 25 +++++++++++++++++++++++++
>> tools/perf/util/evsel.c | 30 +++++++++---------------------
>> tools/perf/util/evsel.h | 1 +
>> 3 files changed, 35 insertions(+), 21 deletions(-)
>>
>> diff --git a/tools/perf/arch/x86/util/evsel.c b/tools/perf/arch/x86/util/evsel.c
>> index 512c2d885d24..9a7141c5a4ea 100644
>> --- a/tools/perf/arch/x86/util/evsel.c
>> +++ b/tools/perf/arch/x86/util/evsel.c
>> @@ -102,3 +102,28 @@ 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 with exclude_{kernel|user|hv|idle|host|guest}=0.");
>> + }
>> +
>> + if (!evsel->core.attr.sample_period) {
>> + return scnprintf(msg, size, "AMD IBS doesn't support counting mode. Try "
>> + "again with sample_{period|freq} with non-zero value.");
>
> Is this for perf stat? We don't allow zero period for perf record.
>
> $ perf record -F 0 true
> frequency and count are zero, aborting
>
> Then maybe it can say: "IBS doesn't support perf stat, Use perf record."
Ok. Let me skip this since generic code is already covering it.
Thanks,
Ravi