Re: [RFC V2 SLEB 00/14] The Enhanced(hopefully) Slab Allocator

From: Pekka Enberg
Date: Tue May 25 2010 - 06:45:26 EST


Hi Nick,

On Tue, May 25, 2010 at 1:19 PM, Nick Piggin <npiggin@xxxxxxx> wrote:
>> Like I said, as a maintainer I'm happy to merge patches to modernize
>> SLAB
>
> I think that would be most productive at this point. I will volunteer
> to do it.

OK, great!

> As much as I would like to see SLQB be merged :) I think the best
> option is to go with SLAB because it is very well tested and very
> very well performing.

I would have liked to see SLQB merged as well but it just didn't happen.

> If Christoph or you or I or anyone have genuine improvements to make
> to the core algorithms, then the best thing to do will just be do
> make incremental changes to SLAB.

I don't see the problem in improving SLUB even if we start modernizing
SLAB. Do you? I'm obviously biased towards SLUB still for the reasons
I already mentioned. I don't want to be a blocker for progress so if I
turn out to be a problem, we should consider changing the
maintainer(s). ;-)

> There are several aspects to this. I think the first one will be to
> actually modernize the code style, simplify the bootstrap process and
> static memory allocations (SLQB goes even further than SLUB in this
> regard), and to pull in debug features from SLUB.
>
> These steps should be made without any changes to core algorithms.
> Alien caches can easily be disabled and at present they are really
> only a problem for big Altixes where it is a known parameter to tune.
>
> From that point, I think we should concede that SLUB has not fulfilled
> performance promises, and make SLAB the default.

Sure. I don't care which allocator "wins" if we actually are able to get there.

Pekka
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