perf: Complete software pmu grouping
Aside from allowing software events into a !software group,
allow adding !software events to pure software groups.
Once we've moved the software group and attached the first
!software event, the group will no longer be a pure software
group and hence no longer be eligible for movement, at which
point the straight ctx comparison is correct again.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20100917093009.410784731@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index ce95617..6d7eef5 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -5184,6 +5184,7 @@
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 @@
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 @@
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 @@
* 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 @@
* 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 @@
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);