[parisc-linux] Progress

Alan Cox alan@lxorguk.ukuu.org.uk
Mon, 22 Nov 1999 09:59:55 +0000 (GMT)

> Now picture the page boundary happes between the two addibs.  This loop will
> execute at about a third of the speed of a normal delay loop.  The code is
> inlined, so only one loop gives you bogus results - if it is the BogoMIPS
> calibration loop, udelay(N) will actually only delay for N/3 us, which can
> have unexpected effects on hardware we use udelay() for.

On x86 things like this, and execution timing differences caused by cache
line alignment and other phase-of-moon issues eventually lead us to not inline
the function. Even then we had to land it on a 32 byte boundary