Denis Chapligin
2010-Mar-01 12:57 UTC
[Xen-devel] domU network slowdown with new dom0 kernel
Hi I have a domU that acts as iSCSI target for our network. It was running on the host with xen 3.4.2 and original XenLinux (2.6.18) kernel. Today i''ve tried to replace old 2.6.18 kernel with a latest (stable/master) pvops kernel. The problem, is that when i replaced dom0 kernel, network performance of domU mentioned above dropped and networking with this domU become totaly unusable. In domU''s dmesg i see the following entries: [ 1785.260012] net eth0: rx->offset: 0, size: 4294967295 [ 1785.260036] net eth0: rx->offset: 0, size: 4294967295 [ 1785.810612] net eth0: rx->offset: 0, size: 4294967295 [ 1785.810612] net eth0: rx->offset: 0, size: 4294967295 [ 1786.310061] net eth0: rx->offset: 0, size: 4294967295 [ 1786.310081] net eth0: rx->offset: 0, size: 4294967295 [ 1786.550007] net eth0: rx->offset: 0, size: 4294967295 [ 1786.550024] net eth0: rx->offset: 0, size: 4294967295 [ 1786.970010] net eth0: rx->offset: 0, size: 4294967295 [ 1786.970025] net eth0: rx->offset: 0, size: 4294967295 [ 1792.840010] __ratelimit: 6 callbacks suppressed [ 1792.840035] net eth0: rx->offset: 0, size: 4294967295 [ 1792.840049] net eth0: rx->offset: 0, size: 4294967295 [ 1798.310016] net eth0: rx->offset: 0, size: 4294967295 [ 1798.310045] net eth0: rx->offset: 0, size: 4294967295 [ 1799.230013] net eth0: rx->offset: 0, size: 4294967295 [ 1799.230036] net eth0: rx->offset: 0, size: 4294967295 [ 1799.550009] net eth0: rx->offset: 0, size: 4294967295 [ 1799.550031] net eth0: rx->offset: 0, size: 4294967295 [ 1800.110352] net eth0: rx->offset: 0, size: 4294967295 [ 1800.110352] net eth0: rx->offset: 0, size: 4294967295 [ 1800.350020] net eth0: rx->offset: 0, size: 4294967295 [ 1800.350050] net eth0: rx->offset: 0, size: 4294967295 in dom0''s dmesg i see nothing interesting. I''ve tried several kernels and found that domU could use any kernel, but dom0 kernel version is critical and it only works with xen 2.6.18 kernel. I have 6 xen hosts, but only this domU is problematic. The domU above is very high loaded and installed on host with 4x1GB ethernet card, combined into single etherchannel. All other domU''s on other hosts and this host aren''t affected and use only 1 NIC and they''re bandwidth usage usually not more than 10-15% of that NIC. The problematic domU uses up to 80% of combined bandwidth. So, what i''m doing wrong and how can i fix this issue? :) -- Denis Chapligin _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Jeremy Fitzhardinge
2010-Mar-01 23:52 UTC
Re: [Xen-devel] domU network slowdown with new dom0 kernel
On 03/01/2010 04:57 AM, Denis Chapligin wrote:> Hi > > I have a domU that acts as iSCSI target for our network. It was running > on the host with xen 3.4.2 and original XenLinux (2.6.18) kernel. Today > i''ve tried to replace old 2.6.18 kernel with a latest (stable/master) > pvops kernel. The problem, is that when i replaced dom0 kernel, network > performance of domU mentioned above dropped and networking with this > domU become totaly unusable. In domU''s dmesg i see the following > entries: > > [ 1785.260012] net eth0: rx->offset: 0, size: 4294967295 > [ 1785.260036] net eth0: rx->offset: 0, size: 4294967295 > [ 1785.810612] net eth0: rx->offset: 0, size: 4294967295 > [ 1785.810612] net eth0: rx->offset: 0, size: 4294967295 > [ 1786.310061] net eth0: rx->offset: 0, size: 4294967295 > [ 1786.310081] net eth0: rx->offset: 0, size: 4294967295 > [ 1786.550007] net eth0: rx->offset: 0, size: 4294967295 > [ 1786.550024] net eth0: rx->offset: 0, size: 4294967295 > [ 1786.970010] net eth0: rx->offset: 0, size: 4294967295 > [ 1786.970025] net eth0: rx->offset: 0, size: 4294967295 > [ 1792.840010] __ratelimit: 6 callbacks suppressed > [ 1792.840035] net eth0: rx->offset: 0, size: 4294967295 > [ 1792.840049] net eth0: rx->offset: 0, size: 4294967295 > [ 1798.310016] net eth0: rx->offset: 0, size: 4294967295 > [ 1798.310045] net eth0: rx->offset: 0, size: 4294967295 > [ 1799.230013] net eth0: rx->offset: 0, size: 4294967295 > [ 1799.230036] net eth0: rx->offset: 0, size: 4294967295 > [ 1799.550009] net eth0: rx->offset: 0, size: 4294967295 > [ 1799.550031] net eth0: rx->offset: 0, size: 4294967295 > [ 1800.110352] net eth0: rx->offset: 0, size: 4294967295 > [ 1800.110352] net eth0: rx->offset: 0, size: 4294967295 > [ 1800.350020] net eth0: rx->offset: 0, size: 4294967295 > [ 1800.350050] net eth0: rx->offset: 0, size: 4294967295 > > in dom0''s dmesg i see nothing interesting. I''ve tried several kernels > and found that domU could use any kernel, but dom0 kernel version is > critical and it only works with xen 2.6.18 kernel. > > I have 6 xen hosts, but only this domU is problematic. The domU above is > very high loaded and installed on host with 4x1GB ethernet card, > combined into single etherchannel. All other domU''s on other hosts > and this host aren''t affected and use only 1 NIC and they''re > bandwidth usage usually not more than 10-15% of that NIC. The > problematic domU uses up to 80% of combined bandwidth. > > So, what i''m doing wrong and how can i fix this issue? :) > >Is this with a freshly checked out version of xen.git? I committed some bugfixes to netback last week, which may have caused problems. J _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel