From 97eaf5300b9d0cd99c310bf8c4a0f2f3296d88a3 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 18 Oct 2009 15:33:50 +0200 Subject: [PATCH] perf/core: Add a callback to perf events A simple callback in a perf event can be used for multiple purposes. For example it is useful for triggered based events like hardware breakpoints that need a callback to dispatch a triggered breakpoint event. v2: Simplify a bit the callback attribution as suggested by Paul Mackerras Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: "K.Prasad" Cc: Alan Stern Cc: Arnaldo Carvalho de Melo Cc: Steven Rostedt Cc: Ingo Molnar Cc: Paul Mackerras Cc: Mike Galbraith Cc: Paul Mundt --- include/linux/perf_event.h | 7 ++++++- kernel/perf_event.c | 14 ++++++++++---- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index fa151d4..8d54e6d 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -544,6 +544,8 @@ struct perf_pending_entry { void (*func)(struct perf_pending_entry *); }; +typedef void (*perf_callback_t)(struct perf_event *, void *); + /** * struct perf_event - performance event kernel representation: */ @@ -639,6 +641,8 @@ struct perf_event { struct event_filter *filter; #endif + perf_callback_t callback; + #endif /* CONFIG_PERF_EVENTS */ }; @@ -748,7 +752,8 @@ extern int perf_event_release_kernel(struct perf_event *event); extern struct perf_event * perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, - pid_t pid); + pid_t pid, + perf_callback_t callback); extern u64 perf_event_read_value(struct perf_event *event); struct perf_sample_data { diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 02d4ff0..5087125 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -4293,6 +4293,7 @@ perf_event_alloc(struct perf_event_attr *attr, struct perf_event_context *ctx, struct perf_event *group_leader, struct perf_event *parent_event, + perf_callback_t callback, gfp_t gfpflags) { const struct pmu *pmu; @@ -4335,6 +4336,11 @@ perf_event_alloc(struct perf_event_attr *attr, event->state = PERF_EVENT_STATE_INACTIVE; + if (!callback && parent_event) + callback = parent_event->callback; + + event->callback = callback; + if (attr->disabled) event->state = PERF_EVENT_STATE_OFF; @@ -4611,7 +4617,7 @@ SYSCALL_DEFINE5(perf_event_open, } event = perf_event_alloc(&attr, cpu, ctx, group_leader, - NULL, GFP_KERNEL); + NULL, NULL, GFP_KERNEL); err = PTR_ERR(event); if (IS_ERR(event)) goto err_put_context; @@ -4668,7 +4674,7 @@ err_put_context: */ struct perf_event * perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, - pid_t pid) + pid_t pid, perf_callback_t callback) { struct perf_event *event; struct perf_event_context *ctx; @@ -4683,7 +4689,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, return NULL ; event = perf_event_alloc(attr, cpu, ctx, NULL, - NULL, GFP_KERNEL); + NULL, callback, GFP_KERNEL); err = PTR_ERR(event); if (IS_ERR(event)) goto err_put_context; @@ -4736,7 +4742,7 @@ inherit_event(struct perf_event *parent_event, child_event = perf_event_alloc(&parent_event->attr, parent_event->cpu, child_ctx, group_leader, parent_event, - GFP_KERNEL); + NULL, GFP_KERNEL); if (IS_ERR(child_event)) return child_event; get_ctx(child_ctx); -- 2.7.4