Re: [patch 2/2] QEMU: decrease console "refresh rate" with -nographic

Carsten Otte
2008-04-15T05:43:46Z

Avi Kivity wrote:
> Anthony Liguori wrote:
>> BTW, when we set O_ASYNC on the tap fd, we're eliminating O_NONBLOCK.
>> This means that we have to poll loop select() when readv()'ing packets
>> instead of just reading until hitting AGAIN. This means at least an
>> extra syscall per packet.
>
> I didn't know that O_ASYNC and O_NONBLOCK were mutually exclusive. Can
> you point me at the relevant documentation?
They should'nt be mutual exclusive. If they are, the tap driver
requires fixing afaics. The relevant documentation is the man page
open(2), and it doesn't state they are exclusive.