init: Remove the BKL from startup code

I have shown by code review that no driver takes
the BKL at init time any more, so whatever the
init code was locking against is no longer there
and it is now safe to remove the BKL there.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Steven Rostedt <rostedt@goodmis>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

diff --git a/init/main.c b/init/main.c
index a42fdf4aeba91ada21882d86d552ed722c00eb5a..9b34c1b8d76c2c25df834fec479d5c46a666b202 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -444,7 +444,6 @@ static noinline void __init_refok rest_init(void)
        kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
        rcu_read_unlock();
        complete(&kthreadd_done);
-       unlock_kernel();
 
        /*
         * The boot idle thread must execute schedule()
@@ -565,7 +564,6 @@ asmlinkage void __init start_kernel(void)
  * Interrupts are still disabled. Do necessary setups, then
  * enable them
  */
-       lock_kernel();
        tick_init();
        boot_cpu_init();
        page_address_init();
@@ -829,7 +827,6 @@ static noinline int init_post(void)
        /* need to finish all async __init code before freeing the memory */
        async_synchronize_full();
        free_initmem();
-       unlock_kernel();
        mark_rodata_ro();
        system_state = SYSTEM_RUNNING;
        numa_default_policy();
@@ -869,8 +866,6 @@ static int __init kernel_init(void * unused)
         * Wait until kthreadd is all set-up.
         */
        wait_for_completion(&kthreadd_done);
-       lock_kernel();
-
        /*
         * init can allocate pages on any node
         */

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 086d3631680505f20d0820371c50b43f4056e316..8047ca5a82378af9f1966b17ed5ec55a5e5231ed 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -734,13 +734,6 @@ __acquires(kernel_lock)
                return -1;
        }
 
-       /*
-        * When this gets called we hold the BKL which means that
-        * preemption is disabled. Various trace selftests however
-        * need to disable and enable preemption for successful tests.
-        * So we drop the BKL here and grab it after the tests again.
-        */
-       unlock_kernel();
        mutex_lock(&trace_types_lock);
 
        tracing_selftest_running = true;
@@ -822,7 +815,6 @@ __acquires(kernel_lock)
 #endif
 
  out_unlock:
-       lock_kernel();
        return ret;
 }