[PATCH v2 4/7] perf: Extend perf_event_aux_ctx() to optionally iterate through more events

Alexander Shishkin
2016-04-27T15:45:44Z

Trace filtering code needs an iterator that can go through all events in
a context, including inactive and filtered, to be able to update their
filters' address ranges based on mmap or exec events.

This patch changes perf_event_aux_ctx() to optionally do this.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
---
kernel/events/core.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index aa3733fc76..6d335f3878 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5790,15 +5790,18 @@ typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data);
static void
perf_event_aux_ctx(struct perf_event_context *ctx,
perf_event_aux_output_cb output,
- void *data)
+ void *data, bool all)
{
struct perf_event *event;

list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
- if (event->state < PERF_EVENT_STATE_INACTIVE)
- continue;
- if (!event_filter_match(event))
- continue;
+ if (!all) {
+ if (event->state < PERF_EVENT_STATE_INACTIVE)
+ continue;
+ if (!event_filter_match(event))
+ continue;
+ }
+
output(event, data);
}
}
@@ -5809,7 +5812,7 @@ perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data,
{
rcu_read_lock();
preempt_disable();
- perf_event_aux_ctx(task_ctx, output, data);
+ perf_event_aux_ctx(task_ctx, output, data, false);
preempt_enable();
rcu_read_unlock();
}
@@ -5839,13 +5842,13 @@ perf_event_aux(perf_event_aux_output_cb output, void *data,
cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
if (cpuctx->unique_pmu != pmu)
goto next;
- perf_event_aux_ctx(&cpuctx->ctx, output, data);
+ perf_event_aux_ctx(&cpuctx->ctx, output, data, false);
ctxn = pmu->task_ctx_nr;
if (ctxn < 0)
goto next;
ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
if (ctx)
- perf_event_aux_ctx(ctx, output, data);
+ perf_event_aux_ctx(ctx, output, data, false);
next:
put_cpu_ptr(pmu->pmu_cpu_context);
}
@@ -5887,10 +5890,10 @@ static int __perf_pmu_output_stop(void *info)
};

rcu_read_lock();
- perf_event_aux_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro);
+ perf_event_aux_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false);
if (cpuctx->task_ctx)
perf_event_aux_ctx(cpuctx->task_ctx, __perf_event_output_stop,
- &ro);
+ &ro, false);
rcu_read_unlock();

return ro.err;
--
2.8.0.rc3