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authorDavidlohr Bueso <dave@stgolabs.net>2017-01-03 13:43:11 -0800
committerIngo Molnar <mingo@kernel.org>2017-01-14 11:14:11 +0100
commit0039962a1473f07fd5c8355bd8264be1eb87eb3e (patch)
tree1611eeff5b2804ebaa7bd89172d85dcd77ac9228
parentaef591cd3d1ddccb268f64c836d38382007373c1 (diff)
downloadlinux-0039962a1473f07fd5c8355bd8264be1eb87eb3e.tar.bz2
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@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave@stgolabs.net Cc: mark.rutland@arm.com Link: http://lkml.kernel.org/r/1483479794-14013-2-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/exit.c22
1 files 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 @@ 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();