Messages in this thread |  | | | Date | Sun, 4 Oct 1998 20:11:43 +0200 | | From | Pavel Machek <> | | Subject | Re: BogoMIPS |
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Hi!
> > > > As a result, 2.0.x just does it as a separate subroutine in > > > > > > > > arch/i386/lib/delay.S > > > > > > > > and that pretty much forces it to not jitter at all. If you'd send me that > > > > kind of patch I'd accept it. > > > > It jitters on cyrix unless you force alignments too. I've not figured out > > the logic that can cause this just that it happens. > > > > > I think the right thing is to use the TSC if the machine has one > > > (which can be trusted.) That leaves only older, simple machines to > > > use timing loops. > > > > That needs the time.c patches to 2.1.x otherwise you cant use non intel > > chips TSC or use the TSC on an APM aware kernel > > This works and gets rid of the two jmps that everybody complained > about.
Are you sure? I saw reports where it depended on place in _page_ (imagine udelay loop at page boundary). So you maybe should .align PAGE_SIZE.
> - "1:\tdecl %0\n\tjns 1b" > + "\tpushl %%cs\n" > + "\tpushl $doit\n" > + "\tlret\n" > + ".align 16\n" > + "doit:\tdecl %%eax\n\tjns doit" > :/* no outputs */ > :"a" (loops) > :"ax");
-- I'm really pavel@atrey.karlin.mff.cuni.cz. Pavel Look at http://atrey.karlin.mff.cuni.cz/~pavel/ ;-).
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