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authorAvi Kivity <avi@redhat.com>2011-06-29 18:42:35 +0300
committerIngo Molnar <mingo@elte.hu>2011-07-01 11:06:38 +0200
commit4dc0da86967d5463708631d02a70cfed5b104884 (patch)
treee09071a62f2457b710ff69df3be1bff39340a4c6 /kernel/events
parent89d6c0b5bdbb1927775584dcf532d98b3efe1477 (diff)
perf: Add context field to perf_event
The perf_event overflow handler does not receive any caller-derived argument, so many callers need to resort to looking up the perf_event in their local data structure. This is ugly and doesn't scale if a single callback services many perf_events. Fix by adding a context parameter to perf_event_create_kernel_counter() (and derived hardware breakpoints APIs) and storing it in the perf_event. The field can be accessed from the callback as event->overflow_handler_context. All callers are updated. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c21
-rw-r--r--kernel/events/hw_breakpoint.c10
2 files changed, 22 insertions, 9 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 81de28dcca8c..ba8e0f4a20e6 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5745,7 +5745,8 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
struct task_struct *task,
struct perf_event *group_leader,
struct perf_event *parent_event,
- perf_overflow_handler_t overflow_handler)
+ perf_overflow_handler_t overflow_handler,
+ void *context)
{
struct pmu *pmu;
struct perf_event *event;
@@ -5803,10 +5804,13 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
#endif
}
- if (!overflow_handler && parent_event)
+ if (!overflow_handler && parent_event) {
overflow_handler = parent_event->overflow_handler;
+ context = parent_event->overflow_handler_context;
+ }
event->overflow_handler = overflow_handler;
+ event->overflow_handler_context = context;
if (attr->disabled)
event->state = PERF_EVENT_STATE_OFF;
@@ -6073,7 +6077,8 @@ SYSCALL_DEFINE5(perf_event_open,
}
}
- event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, NULL);
+ event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
+ NULL, NULL);
if (IS_ERR(event)) {
err = PTR_ERR(event);
goto err_task;
@@ -6258,7 +6263,8 @@ err_fd:
struct perf_event *
perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
struct task_struct *task,
- perf_overflow_handler_t overflow_handler)
+ perf_overflow_handler_t overflow_handler,
+ void *context)
{
struct perf_event_context *ctx;
struct perf_event *event;
@@ -6268,7 +6274,8 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
* Get the target context (task or percpu):
*/
- event = perf_event_alloc(attr, cpu, task, NULL, NULL, overflow_handler);
+ event = perf_event_alloc(attr, cpu, task, NULL, NULL,
+ overflow_handler, context);
if (IS_ERR(event)) {
err = PTR_ERR(event);
goto err;
@@ -6552,7 +6559,7 @@ inherit_event(struct perf_event *parent_event,
parent_event->cpu,
child,
group_leader, parent_event,
- NULL);
+ NULL, NULL);
if (IS_ERR(child_event))
return child_event;
get_ctx(child_ctx);
@@ -6579,6 +6586,8 @@ inherit_event(struct perf_event *parent_event,
child_event->ctx = child_ctx;
child_event->overflow_handler = parent_event->overflow_handler;
+ child_event->overflow_handler_context
+ = parent_event->overflow_handler_context;
/*
* Precalculate sample_data sizes
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 086adf25a55e..b7971d6f38bf 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -431,9 +431,11 @@ int register_perf_hw_breakpoint(struct perf_event *bp)
struct perf_event *
register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered,
+ void *context,
struct task_struct *tsk)
{
- return perf_event_create_kernel_counter(attr, -1, tsk, triggered);
+ return perf_event_create_kernel_counter(attr, -1, tsk, triggered,
+ context);
}
EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
@@ -502,7 +504,8 @@ EXPORT_SYMBOL_GPL(unregister_hw_breakpoint);
*/
struct perf_event * __percpu *
register_wide_hw_breakpoint(struct perf_event_attr *attr,
- perf_overflow_handler_t triggered)
+ perf_overflow_handler_t triggered,
+ void *context)
{
struct perf_event * __percpu *cpu_events, **pevent, *bp;
long err;
@@ -515,7 +518,8 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
get_online_cpus();
for_each_online_cpu(cpu) {
pevent = per_cpu_ptr(cpu_events, cpu);
- bp = perf_event_create_kernel_counter(attr, cpu, NULL, triggered);
+ bp = perf_event_create_kernel_counter(attr, cpu, NULL,
+ triggered, context);
*pevent = bp;