Commit-ID: 0039962a1473f07fd5c8355bd8264be1eb87eb3e
Gitweb: http://git.kernel.org/tip/0039962a1473f07fd5c8355bd8264be1eb87eb3e
Author: Davidlohr Bueso <dave@xxxxxxxxxxxx>
AuthorDate: Tue, 3 Jan 2017 13:43:11 -0800
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sat, 14 Jan 2017 11:14:11 +0100
kernel/exit: Compute 'current' directly
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 argument. This is also a performance win on some
archs such as x86-64 and ppc64 -- arm64 is no longer an issue.
Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: dave@xxxxxxxxxxxx
Cc: mark.rutland@xxxxxxx
Link: http://lkml.kernel.org/r/1483479794-14013-2-git-send-email-dave@xxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/exit.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index 8f14b86..2385d43 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -468,12 +468,12 @@ assign_new_owner:
* 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();
--
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