[Crash-utility] netdump netpoll bug?

[Jeff Moyer]

==> Regarding Re: [Crash-utility] netdump netpoll bug?; "Rohan Mutagi" <rohan208 at gmail.com> adds:

rohan208> My kernel version is 2.6.9-34.EL (my system is "up to date" from
rohan208> RHN)... I am running this inside VMWare and the eth0 is seen as
rohan208> "PCnet/PCI II 79C97OA"

rohan208> I am wondering how do I provide the stack trace? As its on the
rohan208> screen of my laptop. This trace doesnt apper in the "log" file
rohan208> generated by the netdump-server.

Typically, I would recommend a serial console.  I guess that's not possible
with VMWare, though.  ;)

rohan208> Any leads would be appricaited.

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=142269

That bug seems to be private... *sigh*  Here is the stack trace that you
are likely getting:

Call Trace:
 [<f882604d>] pcnet32_start_xmit+0x23/0xf8 [pcnet32]
 [<c0274c78>] netpoll_send_skb+0x6a/0x98
 [<c02751d6>] arp_reply+0x2f7/0x2ff
 [<c027521f>] netpoll_rx+0x41/0x2e4
 [<c026a5c0>] netif_rx+0x1c/0x1b2
 [<f88267e8>] pcnet32_rx+0x2c8/0x325 [pcnet32]
 [<f88261ed>] pcnet32_interrupt+0xcb/0x3fe [pcnet32]
 [<f8824132>] pcnet32_poll_controller+0x16/0x1f [pcnet32]
 [<c0274aa2>] netpoll_poll+0x32/0x8f
 [<f89ef69d>] netpoll_netdump+0xa3/0x478 [netdump]
 [<c01f9a96>] sysrq_handle_crash+0x0/0x8
 [<c01f9a96>] sysrq_handle_crash+0x0/0x8
 [<f89ef5fa>] netpoll_netdump+0x0/0x478 [netdump]
 [<f89ef5f1>] netpoll_start_netdump+0xf1/0xfa [netdump]
 =======================
 ...

Basically, the network transmit queue is busy, and so we call the
poll_controller routine to free up some TX descriptors.  If, in the
process, we end up with ARP requests, we need to service them.  This ends
up in a call to the hard_start_xmit routine inside the pcnet32 driver, and
deadlocks.

Is there possibly another driver that VMWare will mimic?  If not, you can
circumvent this problem by adding an ARP entry for the crashing system to
the netdump server.

-Jeff