Re: pgsql: Further dtrace adjustments for the backend-IDs-in-relpath patch.

On Sun, Aug 15, 2010 at 2:14 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Sat, Aug 14, 2010 at 12:35 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Hrm, this doesn't look right at all.
>
>> Aargh.  I thought I had checked this pretty carefully before
>> committing that last patch.
>
> No, sorry, my mistake: I assumed your first commit hadn't touched the
> probes at all, which I now see wasn't true.  It does appear to be
> consistent now.

OK, good. :-)

>> buffer-flush-start and buffer-flush-done are documented as only
>> getting called for shared buffers, so there is no point in passing a
>> backend ID that will always be -1.  buffer-write-dirty-start and
>> buffer-write-dirty-done are not documented as applying only to shared
>> buffers, but I believe it to be the case: they are called from
>> BufferAlloc, which appears to be shared-buffers-only code.
>
> I wonder though whether we should take the opportunity to generalize the
> probe definitions so that they would work for local buffers.  But maybe
> nobody really cares.

Well, *I* don't care. But I also don't mind it if someone who *does*
care writes a patch. As you can tell, I don't normally enable dtrace
functionality in my builds. :-(

Or to put it another way, I see no particularly compelling reason why
we need to do this right now, but neither do I object to it.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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