diff options
| -rw-r--r-- | include/linux/perf_event.h | 6 | ||||
| -rw-r--r-- | kernel/perf_event.c | 65 |
2 files changed, 66 insertions, 5 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 39d8860b2684..165287fd2cc4 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -804,12 +804,18 @@ struct perf_event { #endif /* CONFIG_PERF_EVENTS */ }; +enum perf_event_context_type { + task_context, + cpu_context, +}; + /** * struct perf_event_context - event context structure * * Used as a container for task events and CPU events as well: */ struct perf_event_context { + enum perf_event_context_type type; struct pmu *pmu; /* * Protect the states of the events in the list, diff --git a/kernel/perf_event.c b/kernel/perf_event.c index ce95617f5d2c..6d7eef5f3c41 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -5184,6 +5184,7 @@ int perf_pmu_register(struct pmu *pmu) cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu); __perf_event_init_context(&cpuctx->ctx); + cpuctx->ctx.type = cpu_context; cpuctx->ctx.pmu = pmu; cpuctx->timer_interval = TICK_NSEC; hrtimer_init(&cpuctx->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); @@ -5517,7 +5518,8 @@ SYSCALL_DEFINE5(perf_event_open, struct perf_event_attr __user *, attr_uptr, pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) { - struct perf_event *event, *group_leader = NULL, *output_event = NULL; + struct perf_event *group_leader = NULL, *output_event = NULL; + struct perf_event *event, *sibling; struct perf_event_attr attr; struct perf_event_context *ctx; struct file *event_file = NULL; @@ -5525,6 +5527,7 @@ SYSCALL_DEFINE5(perf_event_open, struct task_struct *task = NULL; struct pmu *pmu; int event_fd; + int move_group = 0; int fput_needed = 0; int err; @@ -5574,8 +5577,29 @@ SYSCALL_DEFINE5(perf_event_open, * any hardware group. */ pmu = event->pmu; - if ((pmu->task_ctx_nr == perf_sw_context) && group_leader) - pmu = group_leader->pmu; + + if (group_leader && + (is_software_event(event) != is_software_event(group_leader))) { + if (is_software_event(event)) { + /* + * If event and group_leader are not both a software + * event, and event is, then group leader is not. + * + * Allow the addition of software events to !software + * groups, this is safe because software events never + * fail to schedule. + */ + pmu = group_leader->pmu; + } else if (is_software_event(group_leader) && + (group_leader->group_flags & PERF_GROUP_SOFTWARE)) { + /* + * In case the group is a pure software group, and we + * try to add a hardware event, move the whole group to + * the hardware context. + */ + move_group = 1; + } + } if (pid != -1) task = find_lively_task_by_vpid(pid); @@ -5605,8 +5629,14 @@ SYSCALL_DEFINE5(perf_event_open, * Do not allow to attach to a group in a different * task or CPU context: */ - if (group_leader->ctx != ctx) - goto err_context; + if (move_group) { + if (group_leader->ctx->type != ctx->type) + goto err_context; + } else { + if (group_leader->ctx != ctx) + goto err_context; + } + /* * Only a group leader can be exclusive or pinned */ @@ -5626,9 +5656,34 @@ SYSCALL_DEFINE5(perf_event_open, goto err_context; } + if (move_group) { + struct perf_event_context *gctx = group_leader->ctx; + + mutex_lock(&gctx->mutex); + perf_event_remove_from_context(group_leader); + list_for_each_entry(sibling, &group_leader->sibling_list, + group_entry) { + perf_event_remove_from_context(sibling); + put_ctx(gctx); + } + mutex_unlock(&gctx->mutex); + put_ctx(gctx); + } + event->filp = event_file; WARN_ON_ONCE(ctx->parent_ctx); mutex_lock(&ctx->mutex); + + if (move_group) { + perf_install_in_context(ctx, group_leader, cpu); + get_ctx(ctx); + list_for_each_entry(sibling, &group_leader->sibling_list, + group_entry) { + perf_install_in_context(ctx, sibling, cpu); + get_ctx(ctx); + } + } + perf_install_in_context(ctx, event, cpu); ++ctx->generation; mutex_unlock(&ctx->mutex); |