Re: [PATCH 2/9] IB: add a proper completion queue abstraction
From: Jason Gunthorpe
Date: Mon Nov 23 2015 - 17:18:24 EST
On Mon, Nov 23, 2015 at 01:54:05PM -0800, Bart Van Assche wrote:
> Not really ... Please have a look at the SRP initiator source code. What the
> SRP initiator does is to poll the send queue before sending a new
I see that. What I don't see is how SRP handles things when the
sendq fills up, ie the case where __srp_get_tx_iu() == NULL. It looks
like the driver starts to panic and generates printks. I can't tell if
it can survive that, but it doesn't look very good..
It would be a lot better if this wasn't allowed to happen, the polling
loop can run until a sendq becomes available, and never return null
Ie, __srp_get_tx_iu should look more like
Which would be a fairly sane core API for this direct usage.. Ideally
the core code would sleep if possible and not just spin. Maybe also
protect it with a timer.
> command to the target system starts. I think this approach could also be
> used in other ULP drivers if the send queue poll frequency is such that no
> send queue overflow occurs.
Yes, I agree, but it has to be done properly :)
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/