[PATCH RFC V2 07/10] perf tools: change machine comm_exec type to atomic

From: kan . liang
Date: Sun Sep 10 2017 - 22:24:07 EST


From: Kan Liang <kan.liang@xxxxxxxxx>

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

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
---
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 2f1ad29..bbfb9e0 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 64663eb..fb3c2a2 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 threads threads[THREADS__TABLE_SIZE];
--
2.5.5