Messages in this thread |  | | Date | Tue, 2 Jun 2015 09:04:36 -0700 | Subject | Re: [RFC][PATCH 3/4] ntp: Use printk_deferred in leapsecond path | From | John Stultz <> |
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On Tue, Jun 2, 2015 at 3:31 AM, Jiri Bohac <jbohac@suse.cz> wrote: > Hi, > > On Fri, May 29, 2015 at 01:24:27PM -0700, John Stultz wrote: >> Looking over the leapsecond code, I noticed the printk messages >> reporting the leapsecond insertion in the second_overflow path >> were not using the printk_deferred method. This was surprising >> since the printk_deferred method was added in part to avoid >> printk-ing while holding the timekeeping locks. >> >> See 6d9bcb621b0b (timekeeping: use printk_deferred when holding >> timekeeping seqlock) for further rational. >> >> I can only guess that this omission was a git add -p oversight. > > second_overflow() is called from accumulate_nsecs_to_secs(). > > accumulate_nsecs_to_secs() is called from update_wall_time() > - once directly > - once via logarithmic_accumulation() > Both calls are before write_seqcount_begin(&tk_core.seq). > > So it looks safe to use printk there.
Good point. The update is being done to the shadow-timekeeper, so we won't block readers. This can probably be dropped then. Although I'm almost consider keeping it for consistency so I don't forget this again and worry about it in the future.
thanks -john
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