Messages in this thread Patch in this message | | | Date | Mon, 15 Jun 2009 10:36:59 +0200 | From | Stanislaw Gruszka <> | Subject | [PATCH 2/2] posix-cpu-timers: remove tasklist_lock where we can |
| |
tasklist_lock is not needed to protect find_task_by_vpid() nor same_thread_group() and if we replace thread_group_leader() by has_group_leader_pid() we can just use RCU lock to protect some process timers/clocks checks.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> --- kernel/posix-cpu-timers.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index bece7c0..029b442 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -37,13 +37,13 @@ static int check_clock(const clockid_t which_clock) if (pid == 0) return 0; - read_lock(&tasklist_lock); + rcu_read_lock(); p = find_task_by_vpid(pid); if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ? - same_thread_group(p, current) : thread_group_leader(p))) { + same_thread_group(p, current) : has_group_leader_pid(p))) { error = -EINVAL; } - read_unlock(&tasklist_lock); + rcu_read_unlock(); return error; } @@ -398,7 +398,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) new_timer->it.cpu.incr.sched = 0; new_timer->it.cpu.expires.sched = 0; - read_lock(&tasklist_lock); + rcu_read_lock(); if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) { if (pid == 0) { p = current; @@ -412,7 +412,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) p = current->group_leader; } else { p = find_task_by_vpid(pid); - if (p && !thread_group_leader(p)) + if (p && !has_group_leader_pid(p)) p = NULL; } } @@ -422,7 +422,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) } else { ret = -EINVAL; } - read_unlock(&tasklist_lock); + rcu_read_unlock(); return ret; } -- 1.5.5.6
| |