[PATCH RFC 07/10] perf tools: change machine comm_exec type to atomic

[kan . liang]

From: Kan Liang <kan.li...@intel.com>

In case there are two or more threads want to change it.

Signed-off-by: Kan Liang <kan.li...@intel.com>
---
 tools/perf/util/machine.c | 11 ++++++-----
 tools/perf/util/machine.h |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 5e451f9..f568c22 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -64,8 +64,8 @@ int machine__init(struct machine *machine, const char 
*root_dir, pid_t pid)
 
        machine->id_hdr_size = 0;
        machine->kptr_restrict_warned = false;
-       machine->comm_exec = false;
        machine->kernel_start = 0;
+       atomic_set(&machine->comm_exec, 0);
 
        memset(machine->vmlinux_maps, 0, sizeof(machine->vmlinux_maps));
 
@@ -238,14 +238,15 @@ struct machine *machines__add(struct machines *machines, 
pid_t pid,
 
 void machines__set_comm_exec(struct machines *machines, bool comm_exec)
 {
+       int exec = comm_exec ? 1 : 0;
        struct rb_node *nd;
 
-       machines->host.comm_exec = comm_exec;
+       atomic_set(&machines->host.comm_exec, exec);
 
        for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
                struct machine *machine = rb_entry(nd, struct machine, rb_node);
 
-               machine->comm_exec = comm_exec;
+               atomic_set(&machine->comm_exec, exec);
        }
 }
 
@@ -505,7 +506,7 @@ struct thread *machine__find_thread(struct machine 
*machine, pid_t pid,
 struct comm *machine__thread_exec_comm(struct machine *machine,
                                       struct thread *thread)
 {
-       if (machine->comm_exec)
+       if (atomic_read(&machine->comm_exec))
                return thread__exec_comm(thread);
        else
                return thread__comm(thread);
@@ -521,7 +522,7 @@ int machine__process_comm_event(struct machine *machine, 
union perf_event *event
        int err = 0;
 
        if (exec)
-               machine->comm_exec = true;
+               atomic_set(&machine->comm_exec, 1);
 
        if (dump_trace)
                perf_event__fprintf_comm(event, stdout);
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index 745a0ca..ec9a47a 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -38,7 +38,7 @@ struct machine {
        struct rb_node    rb_node;
        pid_t             pid;
        u16               id_hdr_size;
-       bool              comm_exec;
+       atomic_t          comm_exec;
        bool              kptr_restrict_warned;
        char              *root_dir;
        struct machine_th threads[MACHINE_TH_TABLE_SIZE];
-- 
2.5.5