Messages in this thread | | | Date | Wed, 21 Apr 2004 11:30:21 +0530 | From | Hariprasad Nellitheertha <> | Subject | Re: Problem with Netpoll based netdumping and NAPI |
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Hi Matt,
On Mon, Apr 19, 2004 at 12:42:54PM -0500, Matt Mackall wrote: > [changed cc: from linux-net to netdev] > > On Mon, Apr 19, 2004 at 06:21:48PM +0530, Hariprasad Nellitheertha wrote: > > Hi All, > > > > I am facing a problem while trying to network dump using LKCD. My > > debugging so far indicates that this is due to both NAPI and NETPOLL > > being enabled. > > > > I am using LKCD on the 2.6.5 kernel and both the client and server are > > i386 boxes. The dumping machine has an e100 card. I have built the kernel > > with both CONFIG_E100_NAPI and CONFIG_NET_POLL_CONTROLLER (and the other > > netpoll related options) selected. > > > > LKCD uses netpoll for its network dump implementation. The problem we see > > is that the network dump driver does not receive any packet from the > > card driver and hence dumping fails. In e100_intr(), we call > > netif_rx_schedule() if we are using the NAPI feature. netif_rx_schedule, > > in turn, ends up adding the processing of this packet to the NET_RX_SOFTIRQ > > softirq. > > Netpoll should be manually calling the NAPI poll function like this > after calling the interrupt handler (in netpoll_poll()): > > /* If scheduling is stopped, tickle NAPI bits */ > if(trapped && np->dev->poll && > test_bit(__LINK_STATE_RX_SCHED, &np->dev->state)) > np->dev->poll(np->dev, &budget); > > Please ensure that LKCD is calling netpoll_set_trap(1) which tells it > that packet scheduling is stopped.
This was indeed the problem. We were not calling netpoll_set_trap in LKCD. Adding this fixed the problem. Thanks so much for your help with this.
Regards, Hari
> > I've tested this path primarily with tg3 and kgdb-over-ethernet, but > it should be functionally quite similar to e100 and lkcd. > > -- > Matt Mackall : http://www.selenic.com : Linux development and consulting
-- Hariprasad Nellitheertha Linux Technology Center India Software Labs IBM India, Bangalore - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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