Re: [RFC][PATCH] linux-2.5.59_getcycles_A0

From: Martin J. Bligh (
Date: Fri Feb 07 2003 - 20:57:46 EST

>> However this doesn't work on systems w/o a synced TSC, so by simply
> Why not? This shouldn't be performance critical and you can make
> it monotonous with an additional variable + lock if backwards jumps
> should be a problem.
> Also the variations between non synced TSCs should be far below
> any watchdog's radar screen.

Not true. They'll drift further and further apart over time.
Even a 0.01% crystal difference will eventually kill you.

And if that isn't bad enough think about what happens when I run 180 MHz
processors in one node, and 900MHz in another.

You really can't make any assumptions about TSC sync on boxes where
they're not synced.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Fri Feb 07 2003 - 22:00:25 EST