Red Hat Bugzilla – Bug 202971
blkbk/netbk modules don't load
Last modified: 2007-11-30 17:11:40 EST
Description of problem:
modprobe blkbk/netbk fails due to memory allocation failures
Version-Release number of selected component (if applicable):
FATAL: Error inserting blkbk
modprobe: page allocation failure. order:8, mode:0xd0
[<a0000002003cc190>] netback_init+0x190/0x440 [netbk]
Full log attached
I believe this is fixed by
I'll follow up with confirmation on that after testing.
Mentioned changeset doesn't fix this problem.
There are three ways to fix this problem:
(1) link blkback and netback into xen kernel statically instead of as modules.
(2) wait for upstream xen-ia64 to finish xencomm implementation (in progress)
(3) debug the balloon driver issues that cause this problem presently
Of these, I've been working on #3 but may not have a fix soon enough. I think
we should go ahead with #1 while we wait for #2 (which hopefully will be ready
for rhel5 release). Statically linking the blkback and netback modules has no
negative effect on domU, but it enables us to put more effort into testing
fedora/rhel5 xen/ia64, which we can't do well right now.
The xencomm implementation is nearly complete, but I misunderstood that it would
fix the problem. It seems that the real issue is that the netbk and blkbk
drivers need to be loaded ASAP in initramfs instead of deferring them to the
This is basically the same problem as
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=201796 which I think was
A patch which should fix this has been committed upstream to xen-unstable and
Will review and merge.
Just to be clear, the changeset that you point out (11720) is only the last in
the series, which includes:
Yes, that's correct. And there's two smaller additional patches which help
those six above apply more easily. I've got all eight, and they do fix the issue.
Unfortunately for ia64, when a blkfront attaches to a blkback, the machine dies
(I don't have console output to see what happens, I'm assuming dom0 kernel panics).
This bug is still in kernel-xen-2.6.18-1.2784.fc6
If set dom0_mem=1024M in elilo.conf can work around this issue.
also fixed in rawhide on Oct. 13, this bug can be closed