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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2014-10-10 02:44:01 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2015-07-29 15:44:57 +0200 |
| commit | e075867681ca9b8c0b8823e24d0fb4ce3b4f2655 (patch) | |
| tree | c5ab308aecc83571e3598565e9f2d1dd48dead72 /kernel/time/time.c | |
| parent | cbfe8fa6cd672011c755c3cd85c9ffd4e2d10a6f (diff) | |
| download | lwn-e075867681ca9b8c0b8823e24d0fb4ce3b4f2655.tar.gz lwn-e075867681ca9b8c0b8823e24d0fb4ce3b4f2655.zip | |
jiffies: Remove HZ > USEC_PER_SEC special case
HZ never goes much further 1000 and a bit. And if we ever reach one tick
per microsecond, we might be having a problem.
Lets stop maintaining this special case, just leave a paranoid check.
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc; John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'kernel/time/time.c')
| -rw-r--r-- | kernel/time/time.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/kernel/time/time.c b/kernel/time/time.c index 85d5bb1d67eb..ad1bf23e6eb7 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -268,10 +268,14 @@ EXPORT_SYMBOL(jiffies_to_msecs); unsigned int jiffies_to_usecs(const unsigned long j) { -#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ) + /* + * Hz usually doesn't go much further MSEC_PER_SEC. + * jiffies_to_usecs() and usecs_to_jiffies() depend on that. + */ + BUILD_BUG_ON(HZ > USEC_PER_SEC); + +#if !(USEC_PER_SEC % HZ) return (USEC_PER_SEC / HZ) * j; -#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC) - return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC); #else # if BITS_PER_LONG == 32 return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; |