Re: ntpd wedged by libc?

[Dave Hart <hart%ntp.org@localhost>]

On Sun, Mar 18, 2012 at 21:10, Christos Zoulas <christos%zoulas.com@localhost> 
wrote:
> On Mar 18, 12:47pm, agcarver+netbsd%acarver.net@localhost (AGC) wrote:
> -- Subject: Re: ntpd wedged by libc?
>
> | Ok, it seems that the memory leak isn't occuring anymore but there may
> | be an infinite loop problem.  Using the snprintf workaround in ntpd, it
> | still wedged a couple days ago using over 80% CPU.  The memory usage
> | jumped up some (from 5M to 10M) but it did not go beyond that even
> | though I let it run in the wedged condition for hours.
> |
> | The back trace is below.  The daemon was running for about 12 days
> | straight with no problems and then suddenly wedged.
> |
> | Could this be a threads issue?  Reading the header in
> | libc/gdtoa/gdtoimp.h I see that pow5mult is a multithreaded function.
> | Is there a chance for cross thread clobbering or is it just a case of a
> | termination condition not being met in a loop and letting things spin
> | out of control?
>
> Could we be looking at a compiler bug here?

One test going down that road would be to recompile libc (or select
parts) with compiler optimization disabled.  I'm not familiar with the
NetBSD build setup.  Would someone in the know help AGC by describing
how to recompile without optimization on netbsd 5.x sparc32?

Thanks,
Dave Hart