Analysis of the mogilefsd busywait bug

[mischa.z]

That fix seems to close the case. Works great now :)
Thanks,
Mischa


Brad Fitzpatrick wrote:
> Jared,
> 
> I think this is now fixed in svn751...
> 
> Index: lib/MogileFS/Connection/Worker.pm
> ===================================================================
> --- lib/MogileFS/Connection/Worker.pm   (revision 750)
> +++ lib/MogileFS/Connection/Worker.pm   (revision 751)
> @@ -60,6 +60,12 @@
>      }
>  }
> 
> +sub event_write {
> +    my $self = shift;
> +    my $done = $self->write(undef);
> +    $self->watch_write(0) if $done;
> +}
> +
>  sub job {
>      my MogileFS::Connection::Worker $self = shift;
>      return $self->{job} unless @_;
> 
> 
> Let me know?
> 
> 
> 
> 
> On Wed, 28 Feb 2007, Jared Klett wrote:
> 
>> 	I just checked ProcManager.pm and David's patch is in there
>> (svn748).
>>
>> 	I checked the versions on my dependencies and they match as
>> well:
>>
>> Danga::Socket is up to date (1.56).
>> IO::AIO is up to date (2.33).
>>
>> 	Nathan: how large are the files you're writing? I was just able
>> to reproduce by injecting a few files 900 MB in size.
>>
>> cheers,
>>
>> - Jared
>>
>> -----Original Message-----
>> From: mogilefs-bounces at lists.danga.com
>> [mailto:mogilefs-bounces at lists.danga.com] On Behalf Of Nathan Schmidt
>> Sent: Wednesday, February 28, 2007 5:13 PM
>> To: mogilefs at lists.danga.com
>> Subject: Re: Analysis of the mogilefsd busywait bug
>>
>>
>> After applying the patch David Weekly suggested in http://
>> lists.danga.com/pipermail/mogilefs/2007-February/000762.html we've not
>> seen the high CPU usage problem after about a week of 5-20 writes/ sec.
>>
>> 2.6.19.1.pbwiki-grsec #1 SMP i686 GNU/Linux, IO::AIO v2.33,
>> Danga::Socket v1.56
>>
>> Regards,
>> -Nathan / PBwiki
>>
>>
>>
>> On Feb 28, 2007, at 1:45 PM, Brad Fitzpatrick wrote:
>>
>>> I'm still very eager to solve this, but I've been traveling for past
>>> 2+ weeks, away from primary dev environments.
>>>
>>> We need to solve this before we deploy this version of MogileFS into
>>> LJ production, so don't worry -- it'll get fixed.  Hopefully this
>>> week.
>>>
>>> - Brad
>>>
>>>
>>> On Wed, 28 Feb 2007, Jared Klett wrote:
>>>
>>>> 	I hate to be the squeaky wheel, but I'm still seeing the
>> mogilefsd
>>>> taking 100% CPU aka the "busywait" bug after updating to
>>>> svn748 (the latest as of today).
>>>>
>>>> 	I reinitialized my entire MogileFS environment, injected one
>> file,
>>>> and mogilefsd on one of the two tracker servers started spinning at
>>>> 100% CPU.
>>>>
>>>> 	I provided some debug info in this thread:
>>>>
>>>> http://lists.danga.com/pipermail/mogilefs/2007-February/000792.html
>>>>
>>>> 	I checked lsof and strace output and it's pretty much the same
>> story
>>>> I laid out in that post.
>>>>
>>>> 	is there any new info or resolution on this issue?
>>>>
>>>> cheers,
>>>>
>>>> - Jared
>>>>
>>>> -----Original Message-----
>>>> From: mogilefs-bounces at lists.danga.com
>>>> [mailto:mogilefs-bounces at lists.danga.com] On Behalf Of Brad
>>>> Fitzpatrick
>>>> Sent: Wednesday, February 14, 2007 3:23 AM
>>>> To: David Weekly
>>>> Cc: nathan at pbwiki.com; mogilefs at lists.danga.com; Brett G. Durrett
>>>> Subject: Re: Analysis of the mogilefsd busywait bug
>>>>
>>>> Committed in svn740.
>>>>
>>>> On Tue, 13 Feb 2007, David Weekly wrote:
>>
>