exit: __exit_signal: use thread_group_leader() consistently
Cleanup:
- Add the boolean, group_dead = thread_group_leader(), for clarity.
- Do not test/set sig == NULL to detect the all-dead case, use this
boolean.
- Pass this boolen to __unhash_process() and use it instead of another
thread_group_leader() call which needs ->group_leader.
This can be considered as microoptimization, but hopefully this also
allows us do do other cleanups later.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index bbc7906..3602f46 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -58,11 +58,11 @@
static void exit_mm(struct task_struct * tsk);
-static void __unhash_process(struct task_struct *p)
+static void __unhash_process(struct task_struct *p, bool group_dead)
{
nr_threads--;
detach_pid(p, PIDTYPE_PID);
- if (thread_group_leader(p)) {
+ if (group_dead) {
detach_pid(p, PIDTYPE_PGID);
detach_pid(p, PIDTYPE_SID);
@@ -79,6 +79,7 @@
static void __exit_signal(struct task_struct *tsk)
{
struct signal_struct *sig = tsk->signal;
+ bool group_dead = thread_group_leader(tsk);
struct sighand_struct *sighand;
struct tty_struct *uninitialized_var(tty);
@@ -92,7 +93,7 @@
atomic_dec(&sig->count);
posix_cpu_timers_exit(tsk);
- if (thread_group_leader(tsk)) {
+ if (group_dead) {
posix_cpu_timers_exit_group(tsk);
tty = sig->tty;
sig->tty = NULL;
@@ -127,10 +128,9 @@
sig->oublock += task_io_get_oublock(tsk);
task_io_accounting_add(&sig->ioac, &tsk->ioac);
sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
- sig = NULL; /* Marker for below. */
}
- __unhash_process(tsk);
+ __unhash_process(tsk, group_dead);
/*
* Do this under ->siglock, we can race with another thread
@@ -142,7 +142,7 @@
__cleanup_sighand(sighand);
clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
- if (sig) {
+ if (group_dead) {
flush_sigqueue(&sig->shared_pending);
taskstats_tgid_free(sig);
tty_kref_put(tty);