x86: reduce preemption off section in exit thread

Impact: latency improvement

No need to keep preemption disabled over the kfree call.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 6afa523..156f875 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -65,11 +65,11 @@ void exit_thread(void)
 {
        struct task_struct *me = current;
        struct thread_struct *t = &me->thread;
+       unsigned long *bp = t->io_bitmap_ptr;
 
-       if (me->thread.io_bitmap_ptr) {
+       if (bp) {
                struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
 
-               kfree(t->io_bitmap_ptr);
                t->io_bitmap_ptr = NULL;
                clear_thread_flag(TIF_IO_BITMAP);
                /*
@@ -78,6 +78,7 @@ void exit_thread(void)
                memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
                t->io_bitmap_max = 0;
                put_cpu();
+               kfree(bp);
        }
 
        ds_exit_thread(current);