Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH v7] timekeeping: Added a function to return tv_sec portion of ktime_get_ts64() | Date | Wed, 29 Oct 2014 10:37:42 +0100 |
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On Wednesday 29 October 2014 10:21:18 Thomas Gleixner wrote: > On Wed, 29 Oct 2014, Heena Sirwani wrote: > > +time64_t ktime_get_seconds(void) > > +{ > > + time64_t seconds; > > + struct timekeeper *tk = &tk_core.timekeeper; > > + unsigned int seq; > > + > > + WARN_ON(timekeeping_suspended); > > You want to have the same 64bit logic as you did for > ktime_get_real_seconds. So on 64bit it boils down to return > tk->ktime_sec. > > > + > > + do { > > + seq = read_seqcount_begin(&tk_core.seq); > > + seconds = tk->ktime_sec; > > + > > + } while (read_seqcount_retry(&tk_core.seq, seq)); >
I wonder if we should just make tk->ktime_sec 'unsigned long' and avoid the lock for 32-bit as well. Are there any theoretical cases where the monotonic time could overflow a 32-bit integer?
As a minor optimization 's64 nsec_offset' could also be 'long', since that only stores a number that is known to be less than 1000000000.
Arnd
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