exit_irq_thread() clears IRQTF_RUNTHREAD flag and drops the thread's bit in desc->threads_oneshot then. The bit must not be set again in between and it does not, since irq_wake_thread() sees PF_EXITING flag first and returns. Due to above the order or checking PF_EXITING and IRQTF_RUNTHREAD flags in irq_wake_thread() is important. This change just makes it more visible in the source code.
Unified · Split
| @@ -54,14 +54,18 @@ static void warn_no_thread(unsigned int irq, struct irqaction *action) · 53 unmodified lines | |||
| 54 | static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action) | 54 | static void irq_wake_thread(struct irq_desc *desc, struct irqaction *action) |
| 55 | { | 55 | { |
| 56 | /* | 56 | /* |
| 57 | * Wake up the handler thread for this action. In case the | 57 | * In case the thread crashed and was killed we just pretend that |
| 58 | * thread crashed and was killed we just pretend that we | 58 | * we handled the interrupt. The hardirq handler has disabled the |
| 59 | * handled the interrupt. The hardirq handler has disabled the | 59 | * device interrupt, so no irq storm is lurking. |
| 60 | * device interrupt, so no irq storm is lurking. If the | 60 | */ |
| 61 | if (action->thread->flags & PF_EXITING) | ||
| 62 | return; | ||
| 63 | |||
| 64 | /* | ||
| 65 | * Wake up the handler thread for this action. If the | ||
| 61 | * RUNTHREAD bit is already set, nothing to do. | 66 | * RUNTHREAD bit is already set, nothing to do. |
| 62 | */ | 67 | */ |
| 63 | if ((action->thread->flags & PF_EXITING) || | 68 | if (test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags)) |
| 64 | test_and_set_bit(IRQTF_RUNTHREAD, &action->thread_flags)) | ||
| 65 | return; | 69 | return; |
| 66 | 70 | ||
| 67 | /* | 71 | /* |