Re: [Xen-users] kernel 3.9.2 - xen 4.2.2/4.3rc1 => BUG unable to handle kernel paging request netif_poll+0x49c/0xe8

[Wei Liu <wei.liu2@citrix.com>]

Moving discussion to Xen-devel

On Thu, May 16, 2013 at 10:29:56PM +0300, Eugene Istomin wrote:
> Hello,
> 
> I tried to use 3.9.2 kernel with xen 4.2.2/4.3rc1 and in both variants leads 
> to this error in network-intensive load (such as iperf, 100 nginx parallel 
> requests to 1M files and so on):
> 

It would be more helpful if you can provide info on your configurations
(Dom0 and DomU), your workload, how to reproduce the bug.

I run iperf and NFS to test Xen network, but never see any crash like
this myself.

> BUG: unable to handle kernel paging request at ffff8800795a3000
> [   60.246945] IP: [<ffffffffa001a75c>] netif_poll+0x49c/0xe80 [xennet]
> [   60.246975] PGD a8a067 PUD a9a067 PMD 7fc27067 PTE 
> 80100000795a3065
> [   60.247004] Oops: 0003 [#1] SMP 
> [   60.247020] Modules linked in: af_packet hwmon domctl crc32_pclmul 
> crc32c_intel ghash_clmulni_intel aesni_intel ablk_helper cryptd lrw 
> aes_x86_64 joydev xts gf128mul autofs4 scsi_dh_emc scsi_dh_alua 
> scsi_dh_rdac scsi_dh_hp_sw scsi_dh xenblk cdrom xennet ata_generic 
> ata_piix
> [   60.247144] CPU 0 
> [   60.247154] Pid: 0, comm: swapper/0 Not tainted 3.9.2-1.g04040b9-xen 
> #1  
> [   60.247179] RIP: e030:[<ffffffffa001a75c>]  [<ffffffffa001a75c>] 
> netif_poll+0x49c/0xe80 [xennet]
> ...

Could you provide fuul stack trace? AFAICT there is no netif_poll in Xen
netfront/back.

Presumably this is Dom0 log? (from the domctl module)

> 
> We have couple of production hypervisors on 3.4 kernels with high-
> throughput  internal network (VM-to-VM in one Dom0), iperf on them is 
> working well:
> [  3]  0.0- 2.0 sec  3357 MBytes  14080 Mbits/sec
> [  3]  2.0- 4.0 sec  2880 MBytes  12077 Mbits/sec
> [  3]  4.0- 6.0 sec  2909 MBytes  12202 Mbits/sec
> [  3]  6.0- 8.0 sec  2552 MBytes  10702 Mbits/sec
> [  3]  8.0-10.0 sec  3616 MBytes  15166 Mbits/sec
> [  3] 10.0-12.0 sec  3415 MBytes  14324 Mbits/sec
> 
> 
> Seems like a kernel bug, is this related to one of this fixes in linux-next or i 
> need to create new bugreport?
> 
> 1) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=1aaf6d3d3d1e95f4be07e32dd84aa1c93855fbbd
> 2) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=9ecd1a75d977e2e8c48139c7d3efed183f898d94
> 3) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=2810e5b9a7731ca5fce22bfbe12c96e16ac44b6f
> 4) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=03393fd5cc2b6cdeec32b704ecba64dbb0feae3c
> 5) https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=59ccb4ebbc35e36a3c143f2d1355deb75c2e628f
> 

I don't think these patches can fix your problem at first glance.


Wei.