Messages in this thread Patch in this message | | | From | Ingo Molnar <> | Subject | [PATCH 02/10] sched/core: Convert ___assert_task_state() link time assert to BUILD_BUG_ON() | Date | Wed, 8 Feb 2017 19:34:15 +0100 |
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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.
Cc: 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> --- include/linux/sched.h | 3 --- kernel/sched/core.c | 3 +++ 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h index c8e519d0b4a3..54651e828ac4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -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) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e4aa470ed454..675647b0b84b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5229,6 +5229,9 @@ 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) -- 2.7.4
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