Re: Use gcc built-in atomic inc/dec in lock.c

Любен Каравелов <karavelov@mail.bg>

From: Любен Каравелов <karavelov@mail.bg>
To: pgsql-hackers@postgresql.org
Date: 2012-12-14T21:00:10Z
Lists: pgsql-hackers
----- Цитат от Mikko Tiihonen (mikko.tiihonen@nitorcreations.com), на 14.12.2012 в 17:33 -----

> On 12/13/2012 12:19 AM, Peter Geoghegan wrote:
>> On 12 December 2012 22:11, Mikko Tiihonen
>> <mikko.tiihonen@nitorcreations.com> wrote:
>>> noticed a "XXX: It might be worth considering using an atomic fetch-and-add
>>> instruction here, on architectures where that is supported." in lock.c
>>>
>>> Here is my first try at using it.
>>
>> That's interesting, but I have to wonder if there is any evidence that
>> this *is* actually helpful to performance.
> 
> One of my open questions listed in the original email was request for help on
> creating a test case that exercise the code path enough so that it any
> improvements can be measured.
> 

Running pgbench on 16+ cores/threads could stress locking primitives. From my experience even benchmarks run on 8 core systems should tell the difference.

--
Luben Karavelov