| Message ID | 1519431578-11995-1-git-send-email-skannan@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Feb 23, 2018 at 04:19:37PM -0800, Saravana Kannan wrote: > When the event numbers registered by multiple PMUs overlap, the > attr->type value passed to perf_event_create_kernel_counter() is used > to determine which PMU to use to create a perf_event. > > However, when the PMU in question is not a standard PMU (defined in > perf_type_id), there is no way for a kernel client to look up the PMU > type for the PMU of interest and set the attr->type appropriately. > > So, add an API to look up the PMU type by name. That way, the kernel > APIs can function in a fashion similar to the user space interface. > > Signed-off-by: Saravana Kannan <skannan@codeaurora.org> > --- > kernel/events/core.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 96db9ae..5d3df58 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -10310,6 +10310,29 @@ static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) > return err; > } > > +int perf_find_pmu_type_by_name(const char *name) > +{ > + struct pmu *pmu; > + int ret = -1; > + > + mutex_lock(&pmus_lock); > + > + list_for_each_entry(pmu, &pmus, entry) { > + if (!pmu->name || pmu->type < 0) > + continue; > + > + if (!strcmp(name, pmu->name)) { > + ret = pmu->type; > + goto out; > + } > + } > + > +out: > + mutex_unlock(&pmus_lock); > + > + return ret; > +} Not without an in-tree user.
diff --git a/kernel/events/core.c b/kernel/events/core.c index 96db9ae..5d3df58 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10310,6 +10310,29 @@ static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id) return err; } +int perf_find_pmu_type_by_name(const char *name) +{ + struct pmu *pmu; + int ret = -1; + + mutex_lock(&pmus_lock); + + list_for_each_entry(pmu, &pmus, entry) { + if (!pmu->name || pmu->type < 0) + continue; + + if (!strcmp(name, pmu->name)) { + ret = pmu->type; + goto out; + } + } + +out: + mutex_unlock(&pmus_lock); + + return ret; +} + /** * perf_event_create_kernel_counter *
When the event numbers registered by multiple PMUs overlap, the attr->type value passed to perf_event_create_kernel_counter() is used to determine which PMU to use to create a perf_event. However, when the PMU in question is not a standard PMU (defined in perf_type_id), there is no way for a kernel client to look up the PMU type for the PMU of interest and set the attr->type appropriately. So, add an API to look up the PMU type by name. That way, the kernel APIs can function in a fashion similar to the user space interface. Signed-off-by: Saravana Kannan <skannan@codeaurora.org> --- kernel/events/core.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)