Re: [PATCH] Scalable CPU bitmasks

[Andrew Morton]

Denis Vlasenko wrote:
> 
> On 18 March 2002 20:07, Russ Weight wrote:
> >           While systems with more than 32 processors are still
> >   out in the future, these interfaces provide a path for gradual
> >   code migration. One of the primary goals is to provide current
> >   functionality without affecting performance.
> 
> Not so far in the future. "7.52 second kernel compile" thread is about
> timing kernel compile on the 32 CPU SMP box.

The x86 spinlock implementation underflows at 128 CPUs [1].
 
> I don't know whether BUG() in inlines makes them too big,

It does, on all but very recent gcc's.  Strings in inlines
generally cause vast kernel bloatage.

> but _for() _loops_ in inline functions definitely do that.
> Here's one of the overgrown inlines:

Sigh.  There is far too much inlining in Linux.

[1] Untested.

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