RE: [PATCH] genirq: for edge interrupt IRQS_ONESHOT support withirq thread

From: Liu, Chuansheng
Date: Fri Oct 12 2012 - 10:57:28 EST


> On SMP an interrupt which is raised after the ack() again before the
> handler finishes, can invoke another delivery on a different CPU,
> which then sees the IRQ_INPROGESS flag, masks it and flags it
> PENDING. When the primary handler on the first CPU returns, it sees
> the PENDING flag, unmasks and invokes the handler another time.
In this case, when IRQ_INPROGRESS flag is set, on another CPU, it will
mask and ack it, if before the primary handler on the first CPU returns,
the edge interrupt is raised again, it will be lost, right?
So I think set PENDING just confirm one time, it just depends on primary handler
execution time and irq frequency.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/