diff options
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 7529e76a2e36..8065949a865e 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -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, |