Re: [patch -mm] fix SLOB on x64

Ingo Molnar
2005-12-11T20:02:59Z

* Matt Mackall <mpm@selenic.com> wrote:

> On Sun, Dec 11, 2005 at 03:12:17PM +0100, Ingo Molnar wrote:
> >
> > this patch fixes 32-bitness bugs in mm/slob.c. Successfully booted x64
> > with SLOB enabled. (i have switched the PREEMPT_RT feature to use the
> > SLOB allocator exclusively, so it must work on all platforms)
>
> The patch looks fine, but what's this about using SLOB exclusively?
> Fragmentation performance of SLOB is miserable on anything like a
> modern desktop, I think SLOB only makes sense for small machines. The
> locking also suggests dual core at most.

well, this is only an -rt artifact: the SLOB needs zero modifications to
work on PREEMPT_RT, while SLAB needed a risky 66K monster patch. Until
someone simplifies the SLAB conversion to PREEMPT_RT, i'll use the SLOB.

i havent noticed any significant slowdown due to the SLOB. In any case,
we'll give it some workout which should further speed up its upstream
integration - it's looking good so far.

Ingo