diff options
| -rw-r--r-- | include/linux/kernel.h | 21 | ||||
| -rw-r--r-- | include/linux/preempt.h | 38 | ||||
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/sched/core.c | 45 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 4 | ||||
| -rw-r--r-- | lib/smp_processor_id.c | 2 |
6 files changed, 56 insertions, 56 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 2f05e9128201..665837f9a831 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -204,6 +204,7 @@ extern int _cond_resched(void); extern void ___might_sleep(const char *file, int line, int preempt_offset); extern void __might_sleep(const char *file, int line, int preempt_offset); extern void __cant_sleep(const char *file, int line, int preempt_offset); +extern void __cant_migrate(const char *file, int line); /** * might_sleep - annotation for functions that can sleep @@ -227,6 +228,18 @@ extern void __cant_sleep(const char *file, int line, int preempt_offset); # define cant_sleep() \ do { __cant_sleep(__FILE__, __LINE__, 0); } while (0) # define sched_annotate_sleep() (current->task_state_change = 0) + +/** + * cant_migrate - annotation for functions that cannot migrate + * + * Will print a stack trace if executed in code which is migratable + */ +# define cant_migrate() \ + do { \ + if (IS_ENABLED(CONFIG_SMP)) \ + __cant_migrate(__FILE__, __LINE__); \ + } while (0) + /** * non_block_start - annotate the start of section where sleeping is prohibited * @@ -251,6 +264,7 @@ extern void __cant_sleep(const char *file, int line, int preempt_offset); int preempt_offset) { } # define might_sleep() do { might_resched(); } while (0) # define cant_sleep() do { } while (0) +# define cant_migrate() do { } while (0) # define sched_annotate_sleep() do { } while (0) # define non_block_start() do { } while (0) # define non_block_end() do { } while (0) @@ -258,13 +272,6 @@ extern void __cant_sleep(const char *file, int line, int preempt_offset); #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) -#ifndef CONFIG_PREEMPT_RT -# define cant_migrate() cant_sleep() -#else - /* Placeholder for now */ -# define cant_migrate() do { } while (0) -#endif - /** * abs - return absolute value of an argument * @x: the value. If it is unsigned type, it is converted to signed type first. diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 8b43922e65df..6df63cbe8bb0 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -322,7 +322,7 @@ static inline void preempt_notifier_init(struct preempt_notifier *notifier, #endif -#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT) +#ifdef CONFIG_SMP /* * Migrate-Disable and why it is undesired. @@ -382,43 +382,11 @@ static inline void preempt_notifier_init(struct preempt_notifier *notifier, extern void migrate_disable(void); extern void migrate_enable(void); -#elif defined(CONFIG_PREEMPT_RT) +#else static inline void migrate_disable(void) { } static inline void migrate_enable(void) { } -#else /* !CONFIG_PREEMPT_RT */ - -/** - * migrate_disable - Prevent migration of the current task - * - * Maps to preempt_disable() which also disables preemption. Use - * migrate_disable() to annotate that the intent is to prevent migration, - * but not necessarily preemption. - * - * Can be invoked nested like preempt_disable() and needs the corresponding - * number of migrate_enable() invocations. - */ -static __always_inline void migrate_disable(void) -{ - preempt_disable(); -} - -/** - * migrate_enable - Allow migration of the current task - * - * Counterpart to migrate_disable(). - * - * As migrate_disable() can be invoked nested, only the outermost invocation - * reenables migration. - * - * Currently mapped to preempt_enable(). - */ -static __always_inline void migrate_enable(void) -{ - preempt_enable(); -} - -#endif /* CONFIG_SMP && CONFIG_PREEMPT_RT */ +#endif /* CONFIG_SMP */ #endif /* __LINUX_PREEMPT_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 3af9d52fe093..a33f35f68060 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -715,7 +715,7 @@ struct task_struct { const cpumask_t *cpus_ptr; cpumask_t cpus_mask; void *migration_pending; -#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT) +#ifdef CONFIG_SMP unsigned short migration_disabled; #endif unsigned short migration_flags; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e6473ecaab3c..c962922784d1 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1728,8 +1728,6 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) #ifdef CONFIG_SMP -#ifdef CONFIG_PREEMPT_RT - static void __do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask, u32 flags); @@ -1800,8 +1798,6 @@ static inline bool rq_has_pinned_tasks(struct rq *rq) return rq->nr_pinned; } -#endif - /* * Per-CPU kthreads are allowed to run on !active && online CPUs, see * __set_cpus_allowed_ptr() and select_fallback_rq(). @@ -2882,7 +2878,7 @@ void sched_set_stop_task(int cpu, struct task_struct *stop) } } -#else +#else /* CONFIG_SMP */ static inline int __set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask, @@ -2891,10 +2887,6 @@ static inline int __set_cpus_allowed_ptr(struct task_struct *p, return set_cpus_allowed_ptr(p, new_mask); } -#endif /* CONFIG_SMP */ - -#if !defined(CONFIG_SMP) || !defined(CONFIG_PREEMPT_RT) - static inline void migrate_disable_switch(struct rq *rq, struct task_struct *p) { } static inline bool rq_has_pinned_tasks(struct rq *rq) @@ -2902,7 +2894,7 @@ static inline bool rq_has_pinned_tasks(struct rq *rq) return false; } -#endif +#endif /* !CONFIG_SMP */ static void ttwu_stat(struct task_struct *p, int cpu, int wake_flags) @@ -7924,6 +7916,39 @@ void __cant_sleep(const char *file, int line, int preempt_offset) add_taint(TAINT_WARN, LOCKDEP_STILL_OK); } EXPORT_SYMBOL_GPL(__cant_sleep); + +#ifdef CONFIG_SMP +void __cant_migrate(const char *file, int line) +{ + static unsigned long prev_jiffy; + + if (irqs_disabled()) + return; + + if (is_migration_disabled(current)) + return; + + if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) + return; + + if (preempt_count() > 0) + return; + + if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) + return; + prev_jiffy = jiffies; + + pr_err("BUG: assuming non migratable context at %s:%d\n", file, line); + pr_err("in_atomic(): %d, irqs_disabled(): %d, migration_disabled() %u pid: %d, name: %s\n", + in_atomic(), irqs_disabled(), is_migration_disabled(current), + current->pid, current->comm); + + debug_show_held_locks(current); + dump_stack(); + add_taint(TAINT_WARN, LOCKDEP_STILL_OK); +} +EXPORT_SYMBOL_GPL(__cant_migrate); +#endif #endif #ifdef CONFIG_MAGIC_SYSRQ diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 590e6f27068c..f5acb6c5ce49 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1056,7 +1056,7 @@ struct rq { struct cpuidle_state *idle_state; #endif -#if defined(CONFIG_PREEMPT_RT) && defined(CONFIG_SMP) +#ifdef CONFIG_SMP unsigned int nr_pinned; #endif unsigned int push_busy; @@ -1092,7 +1092,7 @@ static inline int cpu_of(struct rq *rq) static inline bool is_migration_disabled(struct task_struct *p) { -#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT) +#ifdef CONFIG_SMP return p->migration_disabled; #else return false; diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c index faaa927ac2c8..1c1dbd300325 100644 --- a/lib/smp_processor_id.c +++ b/lib/smp_processor_id.c @@ -26,7 +26,7 @@ unsigned int check_preemption_disabled(const char *what1, const char *what2) if (current->nr_cpus_allowed == 1) goto out; -#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT) +#ifdef CONFIG_SMP if (current->migration_disabled) goto out; #endif |