sched/core: Convert ___assert_task_state() link time assert to BUILD_BUG_ON()

The length of TASK_STATE_TO_CHAR_STR was still checked using the old
link-time manual error method - convert it to BUILD_BUG_ON(). This
has a couple of advantages:

 - it's more obvious what's going on

 - it reduces the size and complexity of <linux/sched.h>

 - BUILD_BUG_ON() will fail during compilation, with a clearer
   error message than the link time assert.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2017-02-03 12:22:54 +01:00
parent 9ccd27cc2e
commit c930b2c0de
2 changed files with 3 additions and 3 deletions

View file

@ -223,9 +223,6 @@ extern void proc_sched_set_task(struct task_struct *p);
#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn"
extern char ___assert_task_state[1 - 2*!!(
sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
/* Convenience macros for the sake of set_current_state */
#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
#define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)

View file

@ -5233,6 +5233,9 @@ void sched_show_task(struct task_struct *p)
int ppid;
unsigned long state = p->state;
/* Make sure the string lines up properly with the number of task states: */
BUILD_BUG_ON(sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1);
if (!try_get_task_stack(p))
return;
if (state)