ctdb: Adding memory pool for queue callback

[Volker Lendecke]

On Wed, Nov 07, 2018 at 05:58:24PM +0100, Swen Schillig wrote:
> On Wed, 2018-11-07 at 17:47 +0100, Volker Lendecke wrote:
> > On Wed, Nov 07, 2018 at 05:28:04PM +0100, Swen Schillig wrote:
> > > showing values like 
> > > [swen at linux ~]$ ./a.out 
> > > It took 8.963634 seconds to execute 10 million talloc/free cycles.
> > > It took 5.951885 seconds to execute 10 million talloc(pool)/free
> > > cycles.
> > > It took 4.095244 seconds to execute 10 million malloc/free cycles.
> > > 
> > > So, I think there's still enough progress to justify the change.
> > 
> > This is with -O3, right? With -O0 the picture looks entirely
> > different
> > to me. Are you 100% certain your production build uses -O3?
> > 
> 
> are you sure we should test each modification up to all possible
> compiler settings ?
> How many of those tests need to be "positive" and how many could be
> indifferent before a modification is accepted ?

In general, not much. But in my test on a debian stretch VM I got 2%
improvement with -O0, and this definitely was not enough to justify
this. It took me quite a while to find that, sorry for that.

> [swen at linux ~]$ cc talloc_test.c -ltalloc -O0

Well, talloc is still -O2, right? That's where the main work is done.
I would doubt that optimizing the test code itself has as much of an
effect as optimizing talloc.c.

With best regards,

Volker

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