You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@perl.apache.org by "Philippe M. Chiasson" <go...@ectoplasm.org> on 2004/10/13 01:48:22 UTC

[Patch mp2] segfault in worker mpm

I spent quite a lot of time trying to figure out the root cause of this problem
without much success. There is some strange interaction with Perl_load_module()
that's causing this segfault.

I've rewritten that part to use eval_sv() instead and the segfault vanished for
me. As much as I'd like to nail down what the problem is with Perl_load_module(),
for now, I'd be comfortable with this temporary solution if it does solve the
problems for more people than just me.

-- 
--------------------------------------------------------------------------------
Philippe M. Chiasson m/gozer\@(apache|cpan|ectoplasm)\.org/ GPG KeyID : 88C3A5A5
http://gozer.ectoplasm.org/     F9BF E0C2 480E 7680 1AE5 3631 CB32 A107 88C3A5A5

Re: [Patch mp2] segfault in worker mpm

Posted by Geoffrey Young <ge...@modperlcookbook.org>.
>> I'll give it a whirl tonight.  in truth, though, I forget exactly the
>> conditions that were causing it - I'm seeing a segfault now with
>> 2.0.47 (and
>> not 2.0.52) worker in the filter tests that is not reproducable when they
>> are run on their own.
> 
> 
> What filter test were failing ?
> 

attached is my test output - everything is fine until the point that the
output starts, and the last test in the output hangs indefintely (like for 6
hours until I killed it this morning).  unfortunately I didn't keep the
coredump today so I can't backtrace it.  and, as I mentioned, running t/TEST
t/filter passes just fine, so I don't know (and have little other info to
provide, other than this has been happening for at least a week, maybe up to
three).

I'll try to get more info tonight or tomorrow.

--Geoff

Re: [Patch mp2] segfault in worker mpm

Posted by "Philippe M. Chiasson" <go...@ectoplasm.org>.

Geoffrey Young wrote:
>>Before I go ahead and check that in, I'd like to at least get a bit more
>>feedback from the other folks that had been seeing this segfault, and
>>confirmation that this patch _does_ get rid of it.
> 
> 
> I'll give it a whirl tonight.  in truth, though, I forget exactly the
> conditions that were causing it - I'm seeing a segfault now with 2.0.47 (and
> not 2.0.52) worker in the filter tests that is not reproducable when they
> are run on their own.

What filter test were failing ?

> --Geoff
> 

-- 
--------------------------------------------------------------------------------
Philippe M. Chiasson m/gozer\@(apache|cpan|ectoplasm)\.org/ GPG KeyID : 88C3A5A5
http://gozer.ectoplasm.org/     F9BF E0C2 480E 7680 1AE5 3631 CB32 A107 88C3A5A5

Re: [Patch mp2] segfault in worker mpm

Posted by "Philippe M. Chiasson" <go...@ectoplasm.org>.

Stas Bekman wrote:
> Philippe M. Chiasson wrote:
> 
> 
>>So, I guess I should just go ahead with my band-aid fix and we can worry
>>about the _real_ problem later then?
> 
> 
> +1

Band-aid applied!

-- 
--------------------------------------------------------------------------------
Philippe M. Chiasson m/gozer\@(apache|cpan|ectoplasm)\.org/ GPG KeyID : 88C3A5A5
http://gozer.ectoplasm.org/     F9BF E0C2 480E 7680 1AE5 3631 CB32 A107 88C3A5A5

Re: [Patch mp2] segfault in worker mpm

Posted by Stas Bekman <st...@stason.org>.
Philippe M. Chiasson wrote:

> So, I guess I should just go ahead with my band-aid fix and we can worry
> about the _real_ problem later then?

+1

-- 
__________________________________________________________________
Stas Bekman            JAm_pH ------> Just Another mod_perl Hacker
http://stason.org/     mod_perl Guide ---> http://perl.apache.org
mailto:stas@stason.org http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org   http://ticketmaster.com

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
For additional commands, e-mail: dev-help@perl.apache.org


Re: [Patch mp2] segfault in worker mpm

Posted by "Philippe M. Chiasson" <go...@ectoplasm.org>.

Geoffrey Young wrote:
> 
> Geoffrey Young wrote:
> 
>>>Before I go ahead and check that in, I'd like to at least get a bit more
>>>feedback from the other folks that had been seeing this segfault, and
>>>confirmation that this patch _does_ get rid of it.
>>
>>
>>I'll give it a whirl tonight.
> 
> 
> whee!  all tests pass.

Good, I still see failures in ithreads.t on and off, but that's old
news

> nice work.

Bah, there is something seriously strange going on with Perl_load_module()
when provided with a version number. I tried to track it down extensively,
but I couldn't pin it down. Alomst certainly a Perl bug lurking somwehre
in there.

So, I guess I should just go ahead with my band-aid fix and we can worry
about the _real_ problem later then?

> --Geoff
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
> For additional commands, e-mail: dev-help@perl.apache.org
> 
> 

-- 
--------------------------------------------------------------------------------
Philippe M. Chiasson m/gozer\@(apache|cpan|ectoplasm)\.org/ GPG KeyID : 88C3A5A5
http://gozer.ectoplasm.org/     F9BF E0C2 480E 7680 1AE5 3631 CB32 A107 88C3A5A5

Re: [Patch mp2] segfault in worker mpm

Posted by Geoffrey Young <ge...@modperlcookbook.org>.

Geoffrey Young wrote:
>>Before I go ahead and check that in, I'd like to at least get a bit more
>>feedback from the other folks that had been seeing this segfault, and
>>confirmation that this patch _does_ get rid of it.
> 
> 
> I'll give it a whirl tonight.

whee!  all tests pass.

nice work.

--Geoff

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
For additional commands, e-mail: dev-help@perl.apache.org


Re: [Patch mp2] segfault in worker mpm

Posted by Geoffrey Young <ge...@modperlcookbook.org>.
> Before I go ahead and check that in, I'd like to at least get a bit more
> feedback from the other folks that had been seeing this segfault, and
> confirmation that this patch _does_ get rid of it.

I'll give it a whirl tonight.  in truth, though, I forget exactly the
conditions that were causing it - I'm seeing a segfault now with 2.0.47 (and
not 2.0.52) worker in the filter tests that is not reproducable when they
are run on their own.

--Geoff

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
For additional commands, e-mail: dev-help@perl.apache.org


Re: [Patch mp2] segfault in worker mpm

Posted by "Philippe M. Chiasson" <go...@ectoplasm.org>.

Stas Bekman wrote:
> Philippe M. Chiasson wrote:
> 
>>I spent quite a lot of time trying to figure out the root cause of this 
>>problem
>>without much success. There is some strange interaction with 
>>Perl_load_module()
>>that's causing this segfault.
>>
>>I've rewritten that part to use eval_sv() instead and the segfault 
>>vanished for
>>me. As much as I'd like to nail down what the problem is with 
>>Perl_load_module(),
>>for now, I'd be comfortable with this temporary solution if it does 
>>solve the
>>problems for more people than just me.
> 
> 
> +1 to workaround and get _17 out. 

Before I go ahead and check that in, I'd like to at least get a bit more
feedback from the other folks that had been seeing this segfault, and
confirmation that this patch _does_ get rid of it.

> In parallel we will try to design a 
> better solution, not involving B::Deparse.

Absolutely

> We discussed things a bit on 
> irc, but need to put a "spec" out
> 

-- 
--------------------------------------------------------------------------------
Philippe M. Chiasson m/gozer\@(apache|cpan|ectoplasm)\.org/ GPG KeyID : 88C3A5A5
http://gozer.ectoplasm.org/     F9BF E0C2 480E 7680 1AE5 3631 CB32 A107 88C3A5A5

Re: [Patch mp2] segfault in worker mpm

Posted by Stas Bekman <st...@stason.org>.
Philippe M. Chiasson wrote:
> I spent quite a lot of time trying to figure out the root cause of this 
> problem
> without much success. There is some strange interaction with 
> Perl_load_module()
> that's causing this segfault.
> 
> I've rewritten that part to use eval_sv() instead and the segfault 
> vanished for
> me. As much as I'd like to nail down what the problem is with 
> Perl_load_module(),
> for now, I'd be comfortable with this temporary solution if it does 
> solve the
> problems for more people than just me.

+1 to workaround and get _17 out. In parallel we will try to design a 
better solution, not involving B::Deparse. We discussed things a bit on 
irc, but need to put a "spec" out


-- 
__________________________________________________________________
Stas Bekman            JAm_pH ------> Just Another mod_perl Hacker
http://stason.org/     mod_perl Guide ---> http://perl.apache.org
mailto:stas@stason.org http://use.perl.org http://apacheweek.com
http://modperlbook.org http://apache.org   http://ticketmaster.com

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@perl.apache.org
For additional commands, e-mail: dev-help@perl.apache.org