On Mon, Jun 07, 2010 at 08:24:41AM +1000, Herbert Xu wrote:

On Sun, Jun 06, 2010 at 11:13:00PM +0300, Michael S. Tsirkin wrote:

quoted

Actually this code looks strange:
Note that add_buf inicates out of memory
condition with a positive return value, and ring full
(which is not an error!) with -ENOSPC.

Indeed, this ultimately came from

commit 9ab86bbcf8be755256f0a5e994e0b38af6b4d399
Author: Shirley Ma [off-list ref]
Date:   Fri Jan 29 03:20:04 2010 +0000

    virtio_net: Defer skb allocation in receive path Date: Wed, 13 Jan 2010 12:53:38 -0800

(Greg, please don't apply this even though I've just given you
the upstream commit ID that you were asking for :)

where it confuses a memory allocation error with an add_buf failure.

quoted

Possibly the right thing to do is to
1. handle ENOMEM specially
2. fix add_buf to return ENOMEM on error

I think we should make it so that only a memory allocation error
is returned as before.  There is no need for returning the add_buf
error unless add_buf is now doing an allocation itself that needs
to be retried.

That's what my patch did, right? Ack it?

Thanks,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt