RE: [PATCH 1/3] slub: set a criteria for slub node partial adding

[Alex,Shi]

On Wed, 2011-12-14 at 10:36 +0800, David Rientjes wrote:
> On Tue, 13 Dec 2011, David Rientjes wrote:
> 
> > > > 	{
> > > > 	        n->nr_partial++;
> > > > 	-       if (tail == DEACTIVATE_TO_TAIL)
> > > > 	-               list_add_tail(&page->lru, &n->partial);
> > > > 	-       else
> > > > 	-               list_add(&page->lru, &n->partial);
> > > > 	+       list_add_tail(&page->lru, &n->partial);
> > > > 	}
> > > > 
> 
> 2 machines (one netserver, one netperf) both with 16 cores, 64GB memory 
> with netperf-2.4.5 comparing Linus' -git with and without this patch:
> 
> 	threads		SLUB		SLUB+patch
> 	 16		116614		117213 (+0.5%)
> 	 32		216436		215065 (-0.6%)
> 	 48		299991		299399 (-0.2%)
> 	 64		373753		374617 (+0.2%)
> 	 80		435688		435765 (UNCH)
> 	 96		494630		496590 (+0.4%)
> 	112		546766		546259 (-0.1%)
> 
> This suggests the difference is within the noise, so this patch neither 
> helps nor hurts netperf on my setup, as expected.

Thanks for the data. Real netperf is hard to give enough press on SLUB.
but as I mentioned before, I also didn't find real performance change on
my loopback netperf testing. 

I retested hackbench again. about 1% performance increase still exists
on my 2 sockets SNB/WSM and 4 sockets NHM.  and no performance drop for
other machines. 

Christoph, what's comments you like to offer for the results or for this
code change? 



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