trap 12: supervisor write,
page not present on 6.1-STABLE Tue May 16 2006
Stanislaw Halik
sthalik at tehran.lain.pl
Wed Jun 28 15:33:52 UTC 2006
On Wed, Jun 28, 2006, Robert Watson wrote:
>>>> 6.1-STABLE crashed on me. I'm providing a backtrace. Could any of you,
>>>> experienced people, suggest me if it's a hardware problem or is it an
>>>> error inside the OS?
>>> This is a known bug in the TCP code; a large set of outstanding changes
>>> is present in 7.x that will fix the problem when merged. However, I
>>> recently had push-back on merging the larger batch of changes, so am
>>> looking at merging a workaround that will also correct the problem
>>> without the larger set of architectural changes. I hope to have a chance
>>> to look at that in detail this weekend.
>> I'm glad to know that it isn't either unknown or hardware-related. Thank
>> you for your prompt reply!
> Per my earlier e-mail, I had hoped to merge a larger set of changes from
> HEAD that resolve the underlying problem here (that inpcb's can be detached
> from a socket while the socket is still in use), but right now I'm
> deferring merging those changes as they are somewhat risky (as they are
> large). Instead, I've produced a candidate work-around patch, now attached
> to kern/97095. This does not fix the underlying problem, but seeks to
> narrow the window for the race to be exercised by avoiding caching a
> volatile pointer across user memory copying, which under load can result in
> blocking I/O. I would be quite interested in knowing if this resolves the
> problem in practice -- if so, it's a definite short-term merge candidate to
> reduce the symptoms of this problem until the proper fix can be merged.
> http://www.watson.org/~robert/freebsd/netperf/20060628-ip_ctloutput.diff
Thank you for the patch. I'll let you know in few days if the crash
occurs again. It's quite reproducible (crashed yesterday in the same
code path).
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20060628/3f3f320a/attachment.pgp
More information about the freebsd-stable
mailing list