Re: LWLOCK_STATS

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
Cc: Robert Haas <robertmhaas(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: LWLOCK_STATS
Date: 2012-01-07 17:18:23
Message-ID: 19785.1325956703@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
> A couple of weeks ago I wrote a little patch that's similar to
> LWLOCK_STATS, but it prints out % of wallclock time that is spent
> acquiring, releasing, or waiting for a lock. I find that more useful
> than the counters.

I would think that the measurement overhead required to obtain two
wall-clock values for every LWLock touch would be so high as to render
any results from this quite suspect.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2012-01-07 17:30:33 Re: Intermittent regression test failures from index-only plan changes
Previous Message Andres Freund 2012-01-07 16:29:08 Re: pgsphere