diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2021-08-15 23:27:48 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2021-08-17 16:57:17 +0200 |
| commit | 6991436c2b5d91d5358d9914ae2df22b9a1d1dc9 (patch) | |
| tree | d736ebbfdcb39a025c712273067677deead69dfb /kernel/sched | |
| parent | b4bfa3fcfe3b827ddb8b16edd45896caac5a1194 (diff) | |
| download | linux-6991436c2b5d91d5358d9914ae2df22b9a1d1dc9.tar.gz | |
sched/core: Provide a scheduling point for RT locks
RT enabled kernels substitute spin/rwlocks with 'sleeping' variants based on rtmutexes. Blocking on such a lock is similar to preemption versus: - I/O scheduling and worker handling, because these functions might block on another substituted lock, or come from a lock contention within these functions. - RCU considers this like a preemption, because the task might be in a read side critical section. Add a separate scheduling point for this, and hand a new scheduling mode argument to __schedule() which allows, along with separate mode masks, to handle this gracefully from within the scheduler, without proliferating that to other subsystems like RCU. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210815211302.372319055@linutronix.de
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ebc24e136222..c89c1d45dd0b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5829,7 +5829,13 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) */ #define SM_NONE 0x0 #define SM_PREEMPT 0x1 -#define SM_MASK_PREEMPT (~0U) +#define SM_RTLOCK_WAIT 0x2 + +#ifndef CONFIG_PREEMPT_RT +# define SM_MASK_PREEMPT (~0U) +#else +# define SM_MASK_PREEMPT SM_PREEMPT +#endif /* * __schedule() is the main scheduler function. @@ -6134,6 +6140,18 @@ void __sched schedule_preempt_disabled(void) preempt_disable(); } +#ifdef CONFIG_PREEMPT_RT +void __sched notrace schedule_rtlock(void) +{ + do { + preempt_disable(); + __schedule(SM_RTLOCK_WAIT); + sched_preempt_enable_no_resched(); + } while (need_resched()); +} +NOKPROBE_SYMBOL(schedule_rtlock); +#endif + static void __sched notrace preempt_schedule_common(void) { do { |