perf/cgroup: Grow per perf_cpu_context heap storage (c2283c93) · Commits · 戴 / test

kernel/events/core.c

+47 −0

Original line number	Diff line number	Diff line
		@@ -892,6 +892,47 @@ static inline void perf_cgroup_sched_in(struct task_struct *prev,
		rcu_read_unlock();
		}

		static int perf_cgroup_ensure_storage(struct perf_event *event,
		struct cgroup_subsys_state *css)
		{
		struct perf_cpu_context *cpuctx;
		struct perf_event **storage;
		int cpu, heap_size, ret = 0;

		/*
		* Allow storage to have sufficent space for an iterator for each
		* possibly nested cgroup plus an iterator for events with no cgroup.
		*/
		for (heap_size = 1; css; css = css->parent)
		heap_size++;

		for_each_possible_cpu(cpu) {
		cpuctx = per_cpu_ptr(event->pmu->pmu_cpu_context, cpu);
		if (heap_size <= cpuctx->heap_size)
		continue;

		storage = kmalloc_node(heap_size * sizeof(struct perf_event *),
		GFP_KERNEL, cpu_to_node(cpu));
		if (!storage) {
		ret = -ENOMEM;
		break;
		}

		raw_spin_lock_irq(&cpuctx->ctx.lock);
		if (cpuctx->heap_size < heap_size) {
		swap(cpuctx->heap, storage);
		if (storage == cpuctx->heap_default)
		storage = NULL;
		cpuctx->heap_size = heap_size;
		}
		raw_spin_unlock_irq(&cpuctx->ctx.lock);

		kfree(storage);
		}

		return ret;
		}

		static inline int perf_cgroup_connect(int fd, struct perf_event *event,
		struct perf_event_attr *attr,
		struct perf_event *group_leader)
		@@ -911,6 +952,10 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
		goto out;
		}

		ret = perf_cgroup_ensure_storage(event, css);
		if (ret)
		goto out;

		cgrp = container_of(css, struct perf_cgroup, css);
		event->cgrp = cgrp;

		@@ -3440,6 +3485,8 @@ static noinline int visit_groups_merge(struct perf_cpu_context *cpuctx,
		.nr = 0,
		.size = cpuctx->heap_size,
		};

		lockdep_assert_held(&cpuctx->ctx.lock);
		} else {
		event_heap = (struct min_heap){
		.data = itrs,

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