Re: [PATCH] af_packet: Don't use skb after dev_queue_xmit()

[Michael Breuer]

On 1/7/2010 2:55 AM, Michael Breuer wrote:
> On 1/7/2010 2:47 AM, Jarek Poplawski wrote:
> > On Thu, Jan 07, 2010 at 02:20:22AM -0500, Michael Breuer wrote:
> > > ...
> > > Reapplied a couple of earlier patches - still can't do jumbo frames, 
> > > but
> > > the rx errors are gone and speed has improved. Too early to assure that
> > > it's stable.
> > >
> > > Patches that seem to fix the rx drops (all from Stephen):
> > > 1) Patch change to tx_init
> > > 2) Patch to lock netif_device_detach
> > > 3) Patch to sky2_tx_complete to add netif_device_present test
> > > Also in the mix: Jarek's alternative 2
> > BTW, the main difference between alt. 1 and 2 is error notification:
> > alternative 2 doesn't hide some (most) of drops, so, dependending on
> > app, there might be more and faster retransmits. (I don't know what
> > apps used by you (other than dhcp) can depend so much on this.)
> Unless I misread the code, I think that in some cases e skb is 
> actually freed if the cfq (among others perhaps) scheduler returns an 
> error on enqueue (flow control perhaps).  Thus with alternative 1, it 
> is possible that the skb is acted upon after being freed - this would 
> be consistent with the DMAR errors I saw.
>
> > > With this set and mtu=1500 all seems good - decent if not stellar
> > > throughput; no logged errors; no reported packet loss. As before, will
> > > leave running and see if anything falls apart.
> > Good news!
> >
> > Jarek P.
> > --
> > 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/
Bad news - crashed about an hour after I wrote this email - under load - 
same crash as before. Network watchdog... lots of attempts to reset the 
adapter... then hw watchdog rebooted the system.
--
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/