perf thread-stack: Fix thread stack processing for the idle task

perf creates a single 'struct thread' to represent the idle task. That
is because threads are identified by PID and TID, and the idle task
always has PID == TID == 0.

However, there are actually separate idle tasks for each CPU. That
creates a problem for thread stack processing which assumes that each
thread has a single stack, not one stack per CPU.

Fix that by passing through the CPU number, and in the case of the idle
"thread", pick the thread stack from an array based on the CPU number.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20181221120620.9659-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/tools/perf/util/thread-stack.h b/tools/perf/util/thread-stack.h
index f97c00a8c251..1f626f4a1c40 100644
--- a/tools/perf/util/thread-stack.h
+++ b/tools/perf/util/thread-stack.h
@@ -80,14 +80,14 @@ struct call_return_processor {
         void *data;
 };
 
-int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip,
+int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip,
                         u64 to_ip, u16 insn_len, u64 trace_nr);
-void thread_stack__set_trace_nr(struct thread *thread, u64 trace_nr);
-void thread_stack__sample(struct thread *thread, struct ip_callchain *chain,
+void thread_stack__set_trace_nr(struct thread *thread, int cpu, u64 trace_nr);
+void thread_stack__sample(struct thread *thread, int cpu, struct ip_callchain *chain,
                           size_t sz, u64 ip, u64 kernel_start);
 int thread_stack__flush(struct thread *thread);
 void thread_stack__free(struct thread *thread);
-size_t thread_stack__depth(struct thread *thread);
+size_t thread_stack__depth(struct thread *thread, int cpu);
 
 struct call_return_processor *
 call_return_processor__new(int (*process)(struct call_return *cr, void *data),