[squid-users] Re: Squid CPU 100% infinite loop

On 2013-05-28, Stuart Henderson <stu_at_spacehopper.org> wrote:
> On 2013-05-17, Alex Rousskov <rousskov_at_measurement-factory.com> wrote:
>> On 05/17/2013 01:28 PM, Loïc BLOT wrote:
>>
>>> I have found the problem. In fact it's the problem mentionned on my
>>> last mail, is right. Squid FD limit was reached, but squid doesn't
>>> mentionned every time the freeze appear that it's a FD limit
>>> problem, then the debug was so difficult.
>>
>> Squid should warn when it runs out of FDs. If it does not, it is a
>> bug. If you can reproduce this, please open a bug report in bugzilla
>> and post relevant logs there.
>>
>> FWIW, I cannot confirm or deny whether reaching FD limit causes what
>> you call an infinite loop -- there was not enough information in your
>> emails to do that. However, if reaching FD limit causes high CPU
>> usage, it is a [minor] bug.
>
> I've just hit this one, ktrace shows that it's in a tight loop doing
> sched_yield(), I'll try and reproduce on a non-production system and open
> a ticket if I get more details..

I haven't reproduced this in squid yet, but I recently hit a case with
similar symptoms with another threaded program on OpenBSD which hit a loop
on sched_yield if it received a signal while forking, this has now been
fixed in the thread library. So if anyone knows how to reproduce, please
try again after updating src/lib/librthread/rthread_fork.c to r1.8.
Received on Fri Jun 21 2013 - 13:58:15 MDT