From d04b0ad37e4b6ac39a56c823ae76ab37cd044dc7 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 3 Feb 2017 22:07:57 +0100 Subject: sched/headers: Move the PREEMPT_COUNT defines from to These defines are not really part of the scheduler's driver API, but are related to the preempt count - so move them to . Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- include/linux/preempt.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'include/linux/preempt.h') diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 7eeceac52dea..cae461224948 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -55,6 +55,27 @@ /* We use the MSB mostly because its available */ #define PREEMPT_NEED_RESCHED 0x80000000 +#define PREEMPT_DISABLED (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED) + +/* + * Disable preemption until the scheduler is running -- use an unconditional + * value so that it also works on !PREEMPT_COUNT kernels. + * + * Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count(). + */ +#define INIT_PREEMPT_COUNT PREEMPT_OFFSET + +/* + * Initial preempt_count value; reflects the preempt_count schedule invariant + * which states that during context switches: + * + * preempt_count() == 2*PREEMPT_DISABLE_OFFSET + * + * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels. + * Note: See finish_task_switch(). + */ +#define FORK_PREEMPT_COUNT (2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED) + /* preempt_count() and related functions, depends on PREEMPT_NEED_RESCHED */ #include -- cgit v1.2.3