Re: [PATCH] Convert alpha to use arch_gettimeoffset()

From: Richard Henderson
Date: Tue Jun 16 2009 - 13:45:25 EST


john stultz wrote:
On Fri, 2009-06-12 at 00:03 -0700, Richard Henderson wrote:
john stultz wrote:
I suspect the alpha arch could even be further improved to provide and
rpcc() based clocksource, but not having the hardware, I don't feel
comfortable attempting the more complicated conversion (but I'd be glad
to help if anyone else is interested).
Unfortunately this isn't possible. The rpcc value is only 32-bits wide,
and so rolls over in approx 3 to 4 seconds. Thus all the contortions to
try and use the truncated value for sub 1 second adjustments.

That's actually ok. The ACPI PM clocksource on x86 is only 24 bits wide
and wraps every 5 seconds. The generic timekeeping code handles the
wrapping and accumulation for you.
Interesting.
Might you create a patch that does this conversion and apply it on top
of mine?
Unfortunately I don't have working hardware anymore. Perhaps Ivan will be able to help here.


r~
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