Re: [PATCH v4 05/13] arm: perf: conditionally use PERF_PMU_CAP_NO_EXCLUDE
From: Peter Zijlstra <peterz@infradead.org>
Date: 2019-01-08 10:29:30
Also in:
linux-arm-kernel, linuxppc-dev, lkml
On Mon, Jan 07, 2019 at 04:27:22PM +0000, Andrew Murray wrote:
quoted hunk ↗ jump to hunk
@@ -393,9 +386,8 @@ __hw_perf_event_init(struct perf_event *event) /* * Check whether we need to exclude the counter from certain modes. */ + if (armpmu->set_event_filter && + armpmu->set_event_filter(hwc, &event->attr)) { pr_debug("ARM performance counters do not support " "mode exclusion\n"); return -EOPNOTSUPP;
This then requires all set_event_filter() implementations to check all the various exclude options; also, set_event_filter() failing then returns with -EOPNOTSUPP instead of the -EINVAL the CAP_NO_EXCLUDE generates, which is again inconsitent. If I look at (the very first git-grep found me) armv7pmu_set_event_filter(), then I find it returning -EPERM (again inconsistent but irrelevant because the actual value is not preserved) for exclude_idle. But it doesn't seem to check exclude_host at all for example.
quoted hunk ↗ jump to hunk
@@ -867,6 +859,9 @@ int armpmu_register(struct arm_pmu *pmu) if (ret) return ret; + if (!pmu->set_event_filter) + pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE; + ret = perf_pmu_register(&pmu->pmu, pmu->name, -1); if (ret) goto out_destroy;-- 2.7.4