Re: [External] [PATCH v13 3/8] QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX

[Peter Xu]

On Wed, Jun 08, 2022 at 02:37:28AM -0300, Leonardo Bras Soares Passos wrote:
> (1) is not an option, as the interface currently uses ret=1 to make
> sure MSG_ZEROCOPY is getting used,
> I added that so the user of qio_channel can switch off zero-copy if
> it's not getting used, and save some cpu.

Yes (1) is not, but could you explain what do you mean by making sure
MSG_ZEROCOPY being used?  Why is it relevant to the retval here?

I just figured it's a bit weird to return >0 here in flush().

> 
> (2) is not a problem, but I fail to see how useful that would be. Is
> the idea manually keeping track of flush happening?

Yes if we can check this up it'll be good enough to me.  The trace point
could help in some case in the future too to monitor the behavior of kernel
MSG_ERRQUEUE but if you don't like it then it's okay.

-- 
Peter Xu