Re: 'Waiting on lock'

On Wed, 2007-05-30 at 12:27 -0400, Tom Lane wrote:
> Stephen Frost <sfrost(at)snowman(dot)net> writes:
> > * Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
> >> It'd be relatively painless to make that happen as part of the
> >> deadlock-check timeout function, but that's typically only a one-second
> >> delay not a "few seconds". I think it'd likely be overly chatty.
>
> > Yeah, I wouldn't want one per second. Do we already track how long
> > we've been waiting?
>
> No, because we're *asleep*. You'd have to add an additional
> timeout-interrupt reason. Plus there's a ton of interesting questions
> about what's safe to do from an interrupt service routine.
>
> In fact, I am scandalized to see that someone has inserted a boatload
> of elog calls into CheckDeadLock since 8.2 --- that seems entirely
> unsafe. [ checks revision history... ]
>
> 2007-03-03 13:46 momjian
>
> * doc/src/sgml/config.sgml, src/backend/storage/lmgr/deadlock.c,
> src/backend/storage/lmgr/proc.c, src/backend/utils/misc/guc.c,
> src/backend/utils/misc/postgresql.conf.sample,
> src/include/storage/lock.h, src/include/storage/proc.h: Add GUC
> log_lock_waits to log long wait times.
>
> Simon Riggs
>
> Bruce, Simon, kindly fix this or revert it.

'twas me. Looking at it now.

Good news is the semantics are exactly what Stephen has requested...

--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com