Messages in this thread | | | Subject | Re: [PATCH] brcmfmac: cfg80211: use msecs_to_jiffies for time conversion | From | Joe Perches <> | Date | Wed, 18 Mar 2015 00:30:56 -0700 |
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On Wed, 2015-03-18 at 07:44 +0100, Nicholas Mc Guire wrote: > On Tue, 17 Mar 2015, Joe Perches wrote: > > On Tue, 2015-03-17 at 08:06 -0400, Nicholas Mc Guire wrote: > > > Converting milliseconds to jiffies by "val * HZ / 1000" is technically > > > OK but msecs_to_jiffies(val) is the cleaner solution and handles all > > > corner cases correctly. This is a minor API consolidation only and > > > should make things more readable.
> > These API consolidation changes now always have a function > > call when the compiler may have previously been able to > > optimize out the "constant * HZ / 1000" calculation. > > > > Perhaps the [um]secs_to_jiffies calls should be indirected > > with yet another static inline with a __builtin_constant_p() > > test so that the function calls can again be avoided when > > possible. > > will give it a try
OK, thanks.
The tricky bit seems to be the movement of the Makefile for kernel/time/timeconst.h.
BC kernel/time/timeconst.h
as include/linux/time.h would need these calculated #defines
#define MSEC_TO_HZ_MUL32 U64_C(0x80000000) #define MSEC_TO_HZ_ADJ32 U64_C(0x0) #define MSEC_TO_HZ_SHR32 31
and the usec ones too.
That created file would have to be moved from kernel/time/Makefile to some other location that could be in the normal include path like include/linux/timeconst.h so that it can be used by include/linux/time.h
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