Messages in this thread | | | Date | Sat, 18 Jul 2009 11:41:01 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] Delete redundant IRQ_DISABLED check in irq_thread |
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On Sat, 18 Jul 2009, Barry Song wrote: > I guess people call disable_irq to disable the whole execution, > specially to disable the hardirq(then both top and bottom are > blocked). It's really strange the disable operation only blocks the > bottom-half.
The disable blocks both. After the disable no hardirq comes in anymore.
The disabled check in the thread is just to take care of the case when the disable comes in between the hardirq and the thread handler.
That way we avoid doing the full tracking of the hardirq / thread chain simply because it is complex and would produce significant overhead in the fast path for no gain. It could be done, but it's not worth the trouble.
Thanks,
tglx
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