Re: Reduce timing overhead of EXPLAIN ANALYZE using rdtsc? - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Reduce timing overhead of EXPLAIN ANALYZE using rdtsc?
Date
Msg-id 20230123203006.qgqhtxh447qoj4yr@awork3.anarazel.de
Whole thread Raw
In response to Re: Reduce timing overhead of EXPLAIN ANALYZE using rdtsc?  (David Geier <geidav.pg@gmail.com>)
Responses Re: Reduce timing overhead of EXPLAIN ANALYZE using rdtsc?
List pgsql-hackers
Hi,

On 2023-01-23 18:52:44 +0100, David Geier wrote:
> One thing I was wondering about: why did you chose to use a signed instead
> of an unsigned 64-bit integer for the ticks?

That's been the case since my first post in the thread :). Mainly, it seems
easier to detect underflow cases during subtraction that way. And the factor
of 2 in range doesn't change a whole lot.


> > > If you have time to look at the pg_test_timing part, it'd be
> > > appreciated. That's a it larger, and nobody looked at it yet. So I'm a bit
> > > hesitant to push it.
> > I haven't yet pushed the pg_test_timing (nor it's small prerequisite)
> > patch.
> > 
> > I've attached those two patches. Feel free to include them in your series if
> > you want, then the CF entry (and thus cfbot) makes sense again...
> I'll include them in my new patch set and also have a careful look at them.

Thanks.

Greetings,

Andres Freund



pgsql-hackers by date:

Previous
From: Andres Freund
Date:
Subject: Re: Reduce timing overhead of EXPLAIN ANALYZE using rdtsc?
Next
From: Andres Freund
Date:
Subject: Re: Add the ability to limit the amount of memory that can be allocated to backends.