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Re: kern/49323

On Sat, Jul 02, 2016 at 02:35:01PM +0000, Moroo Akira wrote:
>  The patch modifies a mask to Remote IRR flag in IOAPIC.
>  This flag should be 0. It must be read only, so it does not matter how
>  it is 0 or 1. but in Hyper-V guest, "emulated IOAPIC interprets a write
>  of 1 in some unexpected way", according to the commit message of OpenBSD.
>  This causes the de(4) timeout.

That part is clearly.

>  The former is fix for sethwmask/sethwunmask,
>  the latter is for ioapic_mask/ioapic_unmask which are used for INTRSUTUB
>  in vector.S.

This part is clear as well. I'm just asking about replacing the two
consecutive ands with a single of a combined ask. Since the operands are
both constants, that avoids one instruction each and is also easier to
read for humans. Sorry if that wasn't clear.


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