|From:||Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>|
|To:||Robert Haas <robertmhaas(at)gmail(dot)com>|
|Cc:||Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>, pgsql-hackers(at)postgresql(dot)org|
|Subject:||Re: profiling connection overhead|
|Views:||Raw Message | Whole Thread | Download mbox|
Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Wed, Nov 24, 2010 at 2:10 AM, Heikki Linnakangas
> <heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
>> Micro-optimizing that search for the non-zero value helps a little bit
>> (attached). Reduces the percentage shown by oprofile from about 16% to 12%
>> on my laptop.
That "micro-optimization" looks to me like your compiler leaves
something to be desired.
> The first optimization that occurred to me was "remove the loop
Or make it execute only in assert-enabled mode, perhaps.
This check had some use back in the bad old days, but the ResourceOwner
mechanism has probably removed a lot of the argument for it.
The counter-argument might be that failing to remove a buffer pin would
be disastrous; but I can't see that it'd be worse than failing to remove
an LWLock, and we have no belt-and-suspenders-too loop for those.
regards, tom lane
|Next Message||Tom Lane||2010-11-24 15:33:02||Re: final patch - plpgsql: for-in-array|
|Previous Message||Joachim Wieland||2010-11-24 15:19:48||Re: Suggested "easy" TODO: pg_dump --from-list|