Re: [Linux-fbdev-devel] Re: fbcon slowness [was NTP on 2.4.2?]

Maciej W. Rozycki (macro@ds2.pg.gda.pl)
Fri, 6 Apr 2001 21:31:00 +0200 (MET DST)


On Fri, 6 Apr 2001, Andrea Arcangeli wrote:

> ev6 works the way you described AFIK (to flush the write buffer you can use

Thanks for the clarification -- you made me calm down.

> wmb(), note that wmb() semantics doesn't require the cpu to really "flush" but
> just to keep writes oredered across other mb or wmb, but it's basically the
> same from a software point of you and flushing the write buffer synchronously
> obviously provides that semantics). I didn't followed very closely the

Of course -- you only want to do mb (and not wmb) if you need to meet
hw's specific timing or you want to perform a read from a volatile
register of a peripheral device.

> previous part of the thread so I'm not sure what is the issue.

Someone complained of Alpha not having Intel-style MTRRs to set write
combining for fb memory...

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@ds2.pg.gda.pl, PGP key available        +

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