Re: Wait free LW_SHARED acquisition - v0.9

On Thu, Oct 30, 2014 at 6:58 PM, Andres Freund <andres(at)2ndquadrant(dot)com>
wrote:
> On 2014-10-30 18:54:57 +0530, Amit Kapila wrote:
> > On Thu, Oct 30, 2014 at 5:52 PM, Andres Freund <andres(at)2ndquadrant(dot)com>
> > wrote:
> > > Hm. What commit did you apply the series ontop? I managed to
reproduce a
> > > hang, but it was just something that heikki had already fixed...
> > >
> >
> > commit 494affbd900d1c90de17414a575af1a085c3e37a
> > Author: Noah Misch <noah(at)leadboat(dot)com>
> > Date: Sun Oct 12 23:33:37 2014 -0400
> >
> > And, I think you are saying that heikki's commit e0d97d has fixed
> > this issue, in that case I will check once by including that fix?
>
> Well, the hang I was able to reproduce was originally hanging because of
> that. I saw lot of content locks waiting as well, but the "origin" seems
> to have a backend waiting for a xloginsert.
>
> The way I could trigger it quite fast was by first running a read/write
> pgbench and then switch to a readonly one.
>

So what exactly you mean by 'switch to'?
Is it that both read-write and readonly pgbench were running together
or after read-write got finished and then by running read-only pgbench,
you are able to reproduce it?

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com