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perf/core: Remove pmu linear searching code 

Searching for the right pmu by iterating over all pmus is no longer
required since all pmus now *must* be present in the 'pmu_idr' list.
So, remove linear searching code.

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230504110003.2548-4-ravi.bangoria@amd.com
This commit is contained in:
Ravi Bangoria 2023-05-04 16:30:02 +05:30 committed by Peter Zijlstra
parent 2fad201fe3
commit 9551fbb64d
1 changed files with 13 additions and 24 deletions
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37
kernel/events/core.c
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@ -11630,38 +11630,27 @@ static struct pmu *perf_init_event(struct perf_event *event)
}
again:
ret = -ENOENT;
rcu_read_lock();
pmu = idr_find(&pmu_idr, type);
rcu_read_unlock();
if (pmu) {
if (event->attr.type != type && type != PERF_TYPE_RAW &&
!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE))
goto fail;
if (!pmu)
goto fail;
ret = perf_try_init_event(pmu, event);
if (ret == -ENOENT && event->attr.type != type && !extended_type) {
type = event->attr.type;
goto again;
}
if (event->attr.type != type && type != PERF_TYPE_RAW &&
!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE))
goto fail;
if (ret)
pmu = ERR_PTR(ret);
goto unlock;
ret = perf_try_init_event(pmu, event);
if (ret == -ENOENT && event->attr.type != type && !extended_type) {
type = event->attr.type;
goto again;
}
list_for_each_entry_rcu(pmu, &pmus, entry, lockdep_is_held(&pmus_srcu)) {
ret = perf_try_init_event(pmu, event);
if (!ret)
goto unlock;
if (ret != -ENOENT) {
pmu = ERR_PTR(ret);
goto unlock;
}
}
fail:
pmu = ERR_PTR(-ENOENT);
if (ret)
pmu = ERR_PTR(ret);
unlock:
srcu_read_unlock(&pmus_srcu, idx);