sched/core: Convert ___assert_task_state() link time assert to BUILD_BUG_ON() (c930b2c0) · Commits · 戴 / test

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>

include/linux/sched.h

+0 −3

Original line number	Diff line number	Diff line
		@@ -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)

kernel/sched/core.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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)

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