diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2009-09-11 10:28:31 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2009-09-11 10:29:42 +0200 |
| commit | 05e7ff7da78bad3edc1290ed86b4a37da72ced62 (patch) | |
| tree | f7348a9f4f561a53465abea731c2ef59900fd62f /arch/s390/include | |
| parent | ca99dab01dd63dcc413395bd3e75b0be152dfefc (diff) | |
[S390] introduce get_clock_monotonic
Introduce get_clock_monotonic() function which can be used to get a
(fast) timestamp. Resolution is the same as for get_clock(). The
only difference is that the timestamps are monotonic and don't jump
backward or forward.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include')
| -rw-r--r-- | arch/s390/include/asm/timex.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h index cc21e3e20fd..24aa1cda20a 100644 --- a/arch/s390/include/asm/timex.h +++ b/arch/s390/include/asm/timex.h @@ -90,4 +90,18 @@ unsigned long long monotonic_clock(void); extern u64 sched_clock_base_cc; +/** + * get_clock_monotonic - returns current time in clock rate units + * + * The caller must ensure that preemption is disabled. + * The clock and sched_clock_base get changed via stop_machine. + * Therefore preemption must be disabled when calling this + * function, otherwise the returned value is not guaranteed to + * be monotonic. + */ +static inline unsigned long long get_clock_monotonic(void) +{ + return get_clock_xt() - sched_clock_base_cc; +} + #endif |