Messages in this thread Patch in this message | | | From | Saravana Kannan <> | Subject | [PATCH v1 1/2] perf/core: Add API to look up PMU type by name | Date | Fri, 23 Feb 2018 16:19:37 -0800 |
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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; +} + /** * perf_event_create_kernel_counter * -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
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