This patch effectively replaces the tsk pointer dereference
(which is obviously == current), to directly use get_current()
macro. In this case, do_exit() always passes current to exit_mm(),
hence we can simply get rid of the arg. This is also a performance
win on some archs such as x86-64 and ppc64 -- arm64 is no longer
an issue:
https://lkml.org/lkml/2016/12/30/230
Signed-off-by: Davidlohr Bueso <dbu...@suse.de>
---
XXX: do_exit() could further be cleaned up and we'd endup getting
rid of tsk for a lot of the exit_*() calls.
kernel/exit.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index 8f14b866f9f6..2385d434a46e 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -468,12 +468,12 @@ void mm_update_next_owner(struct mm_struct *mm)
* Turn us into a lazy TLB process if we
* aren't already..
*/
-static void exit_mm(struct task_struct *tsk)
+static void exit_mm(void)
{
- struct mm_struct *mm = tsk->mm;
+ struct mm_struct *mm = current->mm;
struct core_state *core_state;
- mm_release(tsk, mm);
+ mm_release(current, mm);
if (!mm)
return;
sync_mm_rss(mm);
@@ -491,7 +491,7 @@ static void exit_mm(struct task_struct *tsk)
up_read(&mm->mmap_sem);
- self.task = tsk;
+ self.task = current;
self.next = xchg(&core_state->dumper.next, &self);
/*
* Implies mb(), the result of xchg() must be visible
@@ -501,22 +501,22 @@ static void exit_mm(struct task_struct *tsk)
complete(&core_state->startup);
for (;;) {
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+ set_task_state(current, TASK_UNINTERRUPTIBLE);
if (!self.task) /* see coredump_finish() */
break;
freezable_schedule();
}
- __set_task_state(tsk, TASK_RUNNING);
+ __set_task_state(current, TASK_RUNNING);
down_read(&mm->mmap_sem);
}
atomic_inc(&mm->mm_count);
- BUG_ON(mm != tsk->active_mm);
+ BUG_ON(mm != current->active_mm);
/* more a memory barrier than a real lock */
- task_lock(tsk);
- tsk->mm = NULL;
+ task_lock(current);
+ current->mm = NULL;
up_read(&mm->mmap_sem);
enter_lazy_tlb(mm, current);
- task_unlock(tsk);
+ task_unlock(current);
mm_update_next_owner(mm);
mmput(mm);
if (test_thread_flag(TIF_MEMDIE))
@@ -823,7 +823,7 @@ void __noreturn do_exit(long code)
tsk->exit_code = code;
taskstats_exit(tsk, group_dead);
- exit_mm(tsk);
+ exit_mm();
if (group_dead)
acct_process();
--
2.6.6
