Thread: Custom GIST getting ERROR: too many LWLocks taken

Custom GIST getting ERROR: too many LWLocks taken

From
Ben Martin
Date:
Hi,
  Perhaps this post is better suited to another PG mailing list? If this
is the cast then apologies up front :/

  I've been playing around with improving some of the GiST code in PG
8.1 to better take advantage of domain knowledge where I am applying it.
I am now getting "ERROR:  too many LWLocks taken" when I create index on
a largish table (about 50Mb index should be generated).

I only get this when shuffling around some index tuples inside
picksplit(). The pointers and left/right splits all seem to be in order
when I return and the smaller indexes I've created using this code are
all fine. My GiST is based on an existing implementation from PG 8.1 so
the allocation of the pages etc should all be fine.

Any hints as to what could be eating up LWLocks in this case?

Thanks.



Attachment

Re: Custom GIST getting ERROR: too many LWLocks taken

From
Oleg Bartunov
Date:
On Sun, 20 Nov 2005, Ben Martin wrote:

> Hi,
>  Perhaps this post is better suited to another PG mailing list? If this
> is the cast then apologies up front :/

pgsql-hackers is more appropriate list

>
>  I've been playing around with improving some of the GiST code in PG
> 8.1 to better take advantage of domain knowledge where I am applying it.
> I am now getting "ERROR:  too many LWLocks taken" when I create index on
> a largish table (about 50Mb index should be generated).
>
> I only get this when shuffling around some index tuples inside
> picksplit(). The pointers and left/right splits all seem to be in order
> when I return and the smaller indexes I've created using this code are
> all fine. My GiST is based on an existing implementation from PG 8.1 so
> the allocation of the pages etc should all be fine.
>
> Any hints as to what could be eating up LWLocks in this case?
>

looks like you're leaking locks. 100 locks is a maximum number of
simultaneous locks (backend/storage/lwlock.c).


> Thanks.
>
>
>

     Regards,
         Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83