[PATCH] MSEC_TO_JIFFIES consolidation
From: Ingo Molnar <mingo@elte.hu>
We have various different implementations of MSEC[S]_TO_JIFFIES and
JIFFIES_TO_MSEC[S]. We recently had a compile-time clash in USB.
Fix all that up.
- The SCTP version was very inefficient. Hopefully this version is accurate
enough.
- Optimise for the HZ=100 and HZ=1000 cases
- This version does round-up, so sleep(9 milliseconds) works OK on 100HZ.
- We still have lots of jiffies_to_msec and msec_to_jiffies implementations.
From: William Lee Irwin III <wli@holomorphy.com>
Optimize the cases where HZ is a divisor of 1000 or vice-versa in
JIFFIES_TO_MSECS() and MSECS_TO_JIFFIES() by allowing the nonvanishing(!)
integral ratios to appear as a parenthesized expressions eligible for
constant folding optimizations.
From: me
Use typesafe inlines for the jiffies-to-millisecond conversion functions.
This means that milliseconds officially takes the type `unsigned int'.
All current callers seem to be OK with that.
Drivers need to be fixed up to use this instead of their private versions.