Re: Please revert [PATCH] user of the jiffies rounding patch: Slab

From: Christoph Lameter
Date: Mon Apr 30 2007 - 13:44:04 EST


On Sat, 28 Apr 2007, Arjan van de Ven wrote:

> > Hmmm... Yes but that looks like it comes from a different function. Slab
> > calls
> >
> > __round_jiffies_relative(HZ, cpu))
> >
> > And its description says:
> >
> > /**
> > *
> > * The exact rounding is skewed for each processor to avoid all
> > * processors firing at the exact same time, which could lead
> > * to lock contention or spurious cache line bouncing.
>
>
> > This is exactly the wrong thing to do.
>
>
> is it?

Umm you did not read the last bit of the description? It talks about
firing all timers on all cpus at once.

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