diff options
Diffstat (limited to 'kernel/rcu/srcutiny.c')
| -rw-r--r-- | kernel/rcu/srcutiny.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 3450c3751ef7..a2e2d516e51b 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -9,6 +9,7 @@ */ #include <linux/export.h> +#include <linux/irq_work.h> #include <linux/mutex.h> #include <linux/preempt.h> #include <linux/rcupdate_wait.h> @@ -41,6 +42,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp) ssp->srcu_idx_max = 0; INIT_WORK(&ssp->srcu_work, srcu_drive_gp); INIT_LIST_HEAD(&ssp->srcu_work.entry); + init_irq_work(&ssp->srcu_irq_work, srcu_tiny_irq_work); return 0; } @@ -84,6 +86,7 @@ EXPORT_SYMBOL_GPL(init_srcu_struct); void cleanup_srcu_struct(struct srcu_struct *ssp) { WARN_ON(ssp->srcu_lock_nesting[0] || ssp->srcu_lock_nesting[1]); + irq_work_sync(&ssp->srcu_irq_work); flush_work(&ssp->srcu_work); WARN_ON(ssp->srcu_gp_running); WARN_ON(ssp->srcu_gp_waiting); @@ -177,6 +180,20 @@ void srcu_drive_gp(struct work_struct *wp) } EXPORT_SYMBOL_GPL(srcu_drive_gp); +/* + * Use an irq_work to defer schedule_work() to avoid acquiring the workqueue + * pool->lock while the caller might hold scheduler locks, causing lockdep + * splats due to workqueue_init() doing a wakeup. + */ +void srcu_tiny_irq_work(struct irq_work *irq_work) +{ + struct srcu_struct *ssp; + + ssp = container_of(irq_work, struct srcu_struct, srcu_irq_work); + schedule_work(&ssp->srcu_work); +} +EXPORT_SYMBOL_GPL(srcu_tiny_irq_work); + static void srcu_gp_start_if_needed(struct srcu_struct *ssp) { unsigned long cookie; @@ -189,7 +206,7 @@ static void srcu_gp_start_if_needed(struct srcu_struct *ssp) WRITE_ONCE(ssp->srcu_idx_max, cookie); if (!READ_ONCE(ssp->srcu_gp_running)) { if (likely(srcu_init_done)) - schedule_work(&ssp->srcu_work); + irq_work_queue(&ssp->srcu_irq_work); else if (list_empty(&ssp->srcu_work.entry)) list_add(&ssp->srcu_work.entry, &srcu_boot_list); } |