Re: [PATCH] SLUB use cmpxchg_local

[Christoph Lameter]

I think the simplest solution may be to leave slub as done in the patch 
that we developed last week. The arch must provide a cmpxchg_local that is 
performance wise the fastest possible. On x86 this is going to be the 
cmpxchg_local on others where cmpxchg is slower than interrupt 
disable/enable this is going to be the emulation that does

interrupt disable

cmpchg simulation

interrupt enable


If we can establish that this is not a performance regression then we have 
a clean solution source code wise. It also minimizes the interrupt holdoff 
for the non-cmpxchg_local arches. However, it means that we will have to 
disable interrupts twice for the slow path. If that is too expensive then 
we need a different solution.


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