Re: LWLock optimization for multicore Power machines

Hi Alexander,

On 3/16/17 1:35 PM, David Steele wrote:
> On 2/21/17 9:54 AM, Bernd Helmle wrote:
>> Am Dienstag, den 14.02.2017, 15:53 +0300 schrieb Alexander Korotkov:
>>> +1
>>> And you could try to use pg_wait_sampling
>>> <https://github.com/postgrespro/pg_wait_sampling> to sampling of wait
>>> events.
>>
>> I've tried this with your example from your blog post[1] and got this:
>>
>> (pgbench scale 1000)
>>
>> pgbench -Mprepared -S -n -c 100 -j 100 -T 300 -P2 pgbench2
>>
>> SELECT-only:
>>
>> SELECT * FROM profile_log ;
>>              ts             |  event_type   |     event     | count
>> ----------------------------+---------------+---------------+-------
>>  2017-02-21 15:21:52.45719  | LWLockNamed   | ProcArrayLock |     8
>>  2017-02-21 15:22:11.19594  | LWLockTranche | lock_manager  |     1
>>  2017-02-21 15:22:11.19594  | LWLockNamed   | ProcArrayLock |    24
>>  2017-02-21 15:22:31.220803 | LWLockNamed   | ProcArrayLock |     1
>>  2017-02-21 15:23:01.255969 | LWLockNamed   | ProcArrayLock |     1
>>  2017-02-21 15:23:11.272254 | LWLockNamed   | ProcArrayLock |     2
>>  2017-02-21 15:23:41.313069 | LWLockNamed   | ProcArrayLock |     1
>>  2017-02-21 15:24:31.37512  | LWLockNamed   | ProcArrayLock |    19
>>  2017-02-21 15:24:41.386974 | LWLockNamed   | ProcArrayLock |     1
>>  2017-02-21 15:26:41.530399 | LWLockNamed   | ProcArrayLock |     1
>> (10 rows)
>>
>> writes pgbench runs have far more events logged, see the attached text
>> file. Maybe this is of interest...
>>
>>
>> [1] http://akorotkov.github.io/blog/2016/03/25/wait_monitoring_9_6/
>
> This patch applies cleanly at cccbdde.  It doesn't break compilation on
> amd64 but I can't test on a Power-based machine
>
> Alexander, have you had a chance to look at Bernd's results?

I'm marking this submission "Waiting for Author" as your input seems to 
be required.

This thread has been idle for a week.  Please respond and/or post a new 
patch by 2017-03-28 00:00 AoE (UTC-12) or this submission will be marked 
"Returned with Feedback".

-- 
-David
david@pgmasters.net