[OpenAFS] Re: kernel panic in 1.4.14.1 on rhel6

Aaron Knister aaronk@umbc.edu
Mon, 15 Aug 2011 16:26:53 -0400


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On Fri, Aug 12, 2011 at 12:01 PM, Andrew Deason <adeason@sinenomine.net>wrote:

> On Thu, 11 Aug 2011 10:11:27 -0400
> Aaron Knister <aaronk@umbc.edu> wrote:
>
> > I know everyone's busy, but out of curiosity has anybody had a chance
> > to look at this? Could it be that it's not even an AFS bug, but a
> > linux kernel issue? I'm getting ready to put a webserver into
> > production and am concerned because I can reliably trigger the
> > mentioned kernel panic using "ab".
>
> I don't think it's likely that it's a linux kernel issue. If you want
> something to try, you can try applying these two patches:
>
>
> http://git.openafs.org/?p=openafs.git;a=commitdiff_plain;h=910f3d4cbba4cd78a8e6afa0b32e37ed7f292d18
>
> http://git.openafs.org/?p=openafs.git;a=commitdiff_plain;h=35835af9bb85b358e4bdd11113b637ac0e52c56b
>
> Those fix what may be a similar issue, but I'm not really sure if it's
> the same thing as here. If that doesn't do it (it's good that you have a
> reliable way of reproducing this), we'll need to look more closely at
> the core (if you don't want to provide it since it probably contains
> file data, instructions can probably be provided, though it's a lot more
> detailed than what we've done so far). Or we can proably go the route of
> giving you debug patches, but I'm not quite sure what to add quite yet.
>
>
Hi Andrew,

Those patches do prevent it from crashing, but also results in a number of
"permission denied" errors from the apache processes under heavy load from
ab. The permission denied errors don't occur with 1.6.0pre7.

Thanks,
Aaron


> --
> Andrew Deason
> adeason@sinenomine.net
>
> _______________________________________________
> OpenAFS-info mailing list
> OpenAFS-info@openafs.org
> https://lists.openafs.org/mailman/listinfo/openafs-info
>



-- 
Aaron Knister
Systems Administrator
Division of Information Technology
University of Maryland, Baltimore County
aaronk@umbc.edu

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<div class=3D"gmail_quote">On Fri, Aug 12, 2011 at 12:01 PM, Andrew Deason =
<span dir=3D"ltr">&lt;<a href=3D"mailto:adeason@sinenomine.net">adeason@sin=
enomine.net</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" styl=
e=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">

On Thu, 11 Aug 2011 10:11:27 -0400<br>
<div class=3D"im">Aaron Knister &lt;<a href=3D"mailto:aaronk@umbc.edu">aaro=
nk@umbc.edu</a>&gt; wrote:<br>
<br>
</div><div class=3D"im">&gt; I know everyone&#39;s busy, but out of curiosi=
ty has anybody had a chance<br>
&gt; to look at this? Could it be that it&#39;s not even an AFS bug, but a<=
br>
&gt; linux kernel issue? I&#39;m getting ready to put a webserver into<br>
&gt; production and am concerned because I can reliably trigger the<br>
&gt; mentioned kernel panic using &quot;ab&quot;.<br>
<br>
</div>I don&#39;t think it&#39;s likely that it&#39;s a linux kernel issue.=
 If you want<br>
something to try, you can try applying these two patches:<br>
<br>
<a href=3D"http://git.openafs.org/?p=3Dopenafs.git;a=3Dcommitdiff_plain;h=
=3D910f3d4cbba4cd78a8e6afa0b32e37ed7f292d18" target=3D"_blank">http://git.o=
penafs.org/?p=3Dopenafs.git;a=3Dcommitdiff_plain;h=3D910f3d4cbba4cd78a8e6af=
a0b32e37ed7f292d18</a><br>


<a href=3D"http://git.openafs.org/?p=3Dopenafs.git;a=3Dcommitdiff_plain;h=
=3D35835af9bb85b358e4bdd11113b637ac0e52c56b" target=3D"_blank">http://git.o=
penafs.org/?p=3Dopenafs.git;a=3Dcommitdiff_plain;h=3D35835af9bb85b358e4bdd1=
1113b637ac0e52c56b</a><br>


<br>
Those fix what may be a similar issue, but I&#39;m not really sure if it&#3=
9;s<br>
the same thing as here. If that doesn&#39;t do it (it&#39;s good that you h=
ave a<br>
reliable way of reproducing this), we&#39;ll need to look more closely at<b=
r>
the core (if you don&#39;t want to provide it since it probably contains<br=
>
file data, instructions can probably be provided, though it&#39;s a lot mor=
e<br>
detailed than what we&#39;ve done so far). Or we can proably go the route o=
f<br>
giving you debug patches, but I&#39;m not quite sure what to add quite yet.=
<br>
<font color=3D"#888888"><br></font></blockquote><div><br></div><div>Hi Andr=
ew,=A0</div><div><br></div><div>Those patches do prevent it from crashing, =
but also results in a number of &quot;permission denied&quot; errors from t=
he apache processes under heavy load from ab. The permission denied errors =
don&#39;t occur with 1.6.0pre7.</div>

<div><br></div><div>Thanks,</div><div>Aaron</div><div>=A0</div><blockquote =
class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid=
;padding-left:1ex;"><font color=3D"#888888">
--<br>
</font><div><div></div><div class=3D"h5">Andrew Deason<br>
<a href=3D"mailto:adeason@sinenomine.net">adeason@sinenomine.net</a><br>
<br>
_______________________________________________<br>
OpenAFS-info mailing list<br>
<a href=3D"mailto:OpenAFS-info@openafs.org">OpenAFS-info@openafs.org</a><br=
>
<a href=3D"https://lists.openafs.org/mailman/listinfo/openafs-info" target=
=3D"_blank">https://lists.openafs.org/mailman/listinfo/openafs-info</a><br>
</div></div></blockquote></div><br><br clear=3D"all"><div><br></div>-- <br>=
Aaron Knister<br>Systems Administrator<br>Division of Information Technolog=
y<br>University of Maryland, Baltimore County<br><a href=3D"mailto:aaronk@u=
mbc.edu" target=3D"_blank">aaronk@umbc.edu</a><br>



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