Re: [PATCH RT 00/02] SLOB optimizations

Pekka J Enberg
2005-12-21T07:17:08Z

Hi Ingo,

Steven Rostedt <rostedt@goodmis.org> wrote:
> > [...] Today's slab system is starting to become like the IDE where
> > nobody, but a select few sado-masochis, dare to venture in. (I've CC'd
> > them ;) [...]

On Wed, 21 Dec 2005, Ingo Molnar wrote:
> while it could possibly be cleaned up a bit, it's one of the
> best-optimized subsystems Linux has. Most of the "unnecessary
> complexity" in SLAB is related to a performance or a debugging feature.
> Many times i have looked at the SLAB code in a disassembler, right next
> to profile output from some hot workload, and have concluded: 'I couldnt
> do this any better even with hand-coded assembly'.
>
> SLAB-bashing has become somewhat fashionable, but i really challenge
> everyone to improve the SLAB code first (to make it more modular, easier
> to read, etc.), before suggesting replacements.

I dropped working on the replacement because I wanted to do just that. I
sent my patch only because Matt and Steve talked about writing a
replacement and thought they would be interested to see it.

I am all for gradual improvements but after taking a stab at it, I
starting to think rewriting would be easier, simply because the slab
allocator has been clean-up resistant for so long.

Pekka