lkl: irq: atomically drain pending IRQs#640
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Pending IRQs can be published from host threads while the LKL CPU is owned elsewhere or while interrupts are disabled. Avoid checking the IRQ pending bitmaps with plain loads before the atomic fetch-and-clear, as that can race with concurrent updates and skip newly published work. Also keep draining the index bitmap until it becomes empty, so IRQs queued while earlier pending IRQs are being handled are delivered in the same pass instead of waiting for a later run_irqs() invocation. Signed-off-by: clingfei <chenglingfei@foxmail.com>
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Pending IRQs can be published from host threads while the LKL CPU is owned elsewhere or while interrupts are disabled. Avoid checking the IRQ pending bitmaps with plain loads before the atomic fetch-and-clear, as that can race with concurrent updates and skip newly published work.
Also keep draining the index bitmap until it becomes empty, so IRQs queued while earlier pending IRQs are being handled are delivered in the same pass instead of waiting for a later run_irqs() invocation.