Re: SMP buildworld times / performance tests

[Poul-Henning Kamp]

In message <[EMAIL PROTECTED]>, Bruce Ev
ans writes:
>On Wed, 29 Mar 2000, Mike Smith wrote:
>
>> Just following on from this, one thing that I can see immediately being 
>> very important to me at least is a spinlock in the timecounter structure. 
>> Calcru and various other things call microtime(), and we're going to want 
>> to lock out updates and parallel accesses to the timecounter.  What 
>> should we be using for an interrupt-disabling spinlock?
>
>Nothing.  Accesses to the timecounter struct are already MP safe and fast.
>Only the i8254 timecounter hardware currently needs interrupt-disabling,
>but it is hopefully never used on SMP machines.

Worse.  It is used by default on SMP machines which don't sport the
PIIX timecounter.

--
Poul-Henning Kamp             FreeBSD coreteam member
[EMAIL PROTECTED]               "Real hackers run -current on their laptop."
FreeBSD -- It will take a long time before progress goes too far!


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