Re: Wait free LW_SHARED acquisition - v0.9

On Sat, Oct 11, 2014 at 6:29 AM, Andres Freund <andres(at)2ndquadrant(dot)com>
wrote:
>
> On 2014-10-11 06:18:11 +0530, Amit Kapila wrote:
> I've run some short tests on hydra:
>
> scale 1000:
>
> base:
> 4GB:
> tps = 296273.004800 (including connections establishing)
> tps = 296373.978100 (excluding connections establishing)
>
> 8GB:
> tps = 338001.455970 (including connections establishing)
> tps = 338177.439106 (excluding connections establishing)
>
> base + freelist:
> 4GB:
> tps = 297057.523528 (including connections establishing)
> tps = 297156.987418 (excluding connections establishing)
>
> 8GB:
> tps = 335123.867097 (including connections establishing)
> tps = 335239.122472 (excluding connections establishing)
>
> base + LW_SHARED:
> 4GB:
> tps = 296262.164455 (including connections establishing)
> tps = 296357.524819 (excluding connections establishing)
> 8GB:
> tps = 336988.744742 (including connections establishing)
> tps = 337097.836395 (excluding connections establishing)
>
> base + LW_SHARED + freelist:
> 4GB:
> tps = 296887.981743 (including connections establishing)
> tps = 296980.231853 (excluding connections establishing)
>
> 8GB:
> tps = 345049.062898 (including connections establishing)
> tps = 345161.947055 (excluding connections establishing)
>
> I've also run some preliminary tests using scale=3000 - and I couldn't
> see a performance difference either.
>
> Note that all these are noticeably faster than your results.

What is the client count?
Could you please post numbers you are getting for 3000 scale
factor for client count 128 and 175?

> > Nothing specific, for performance tests where I have to take profiles
> > I use below:
> > ./configure --prefix=<installation_path>
CFLAGS="-fno-omit-frame-pointer"
> > make
>
> Hah. Doing so overwrites the CFLAGS configure normally sets. Check
> # CFLAGS are selected so:
> # If the user specifies something in the environment, that is used.
> # else: If the template file set something, that is used.
> # else: If coverage was enabled, don't set anything.
> # else: If the compiler is GCC, then we use -O2.
> # else: If the compiler is something else, then we use -O, unless
debugging.
>
> so, if you do like above, you're compiling without optimizations... So,
> include at least -O2 as well.

Hmm. okay, but is this required when we do actual performance
tests, because for that currently I don't use CFLAGS.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com