Re: BUG #6629: Creating a gist index fails with "too many LWLocks taken"

On 11.05.2012 16:56, Simon Riggs wrote:
> On 11 May 2012 11:07, Heikki Linnakangas
> <heikki.linnakangas@enterprisedb.com>  wrote:
>
>> I wonder if we should reserve a few of the lwlock "slots" for critical
>> sections, to make this less likely to happen. Not only in this case, but in
>> general. We haven't seen this problem often, but it would be quite trivial
>> to reserve a few slots.
>
> Why reserve them solely for critical sections?

Because if you run out of lwlocks in a critical section, you get a PANIC.

> What is the downside from having>100 slots for general use.
>
> ISTM we should have 250 slots and log a warning if we ever hit 50 or more.

Then we would be back to square one, if a piece of code acquires 250
locks, then enters a critical section, and tries to acquire one more
lock -> PANIC.

--
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com