Re: [git pull] more SLUB updates for 2.6.25

From: Andi Kleen
Date: Fri Feb 08 2008 - 09:58:25 EST


Eric Dumazet <dada1@xxxxxxxxxxxxx> writes:
>
> What about IRQ masking then ?
>
> Many CPU pay high cost for cli/sti pair...

Many? In the x86 world only P4. On the other cores cli/sti (and even
pushf ; cli ; popf) is reasonably fast.

>
> And SLAB/SLUB allocators, even if only used from process context, want
> to disable/re-enable interrupts...
>
> I understand kmalloc() want generic pools, but dedicated pools could
> avoid this cli/sti

While there are a lot of P4s around they are obsolete by now and I would
advise against major redesigns for tuning obsolete CPUs.

-Andi
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