[PATCH 2/9] perf: Allow pmu to choose cpu on which to install event

Yan, Zheng
2012-05-02T02:07:51Z

From: "Yan, Zheng" <zheng.z.yan@intel.com>

Allow the pmu->event_init callback to change event->cpu, so pmu can
choose cpu on which to install event.

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
---
kernel/events/core.c | 13 +++++++++----
1 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 32cfc76..84911de 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6250,6 +6250,8 @@ SYSCALL_DEFINE5(perf_event_open,
}
}

+ get_online_cpus();
+
event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
NULL, NULL);
if (IS_ERR(event)) {
@@ -6302,7 +6304,7 @@ SYSCALL_DEFINE5(perf_event_open,
/*
* Get the target context (task or percpu):
*/
- ctx = find_get_context(pmu, task, cpu);
+ ctx = find_get_context(pmu, task, event->cpu);
if (IS_ERR(ctx)) {
err = PTR_ERR(ctx);
goto err_alloc;
@@ -6375,20 +6377,22 @@ SYSCALL_DEFINE5(perf_event_open,
mutex_lock(&ctx->mutex);

if (move_group) {
- perf_install_in_context(ctx, group_leader, cpu);
+ perf_install_in_context(ctx, group_leader, event->cpu);
get_ctx(ctx);
list_for_each_entry(sibling, &group_leader->sibling_list,
group_entry) {
- perf_install_in_context(ctx, sibling, cpu);
+ perf_install_in_context(ctx, sibling, event->cpu);
get_ctx(ctx);
}
}

- perf_install_in_context(ctx, event, cpu);
+ perf_install_in_context(ctx, event, event->cpu);
++ctx->generation;
perf_unpin_context(ctx);
mutex_unlock(&ctx->mutex);

+ put_online_cpus();
+
event->owner = current;

mutex_lock(&current->perf_event_mutex);
@@ -6417,6 +6421,7 @@ SYSCALL_DEFINE5(perf_event_open,
err_alloc:
free_event(event);
err_task:
+ put_online_cpus();
if (task)
put_task_struct(task);
err_group_fd:
--
1.7.7.6