]> git.baikalelectronics.ru Git - kernel.git/commit
timekeeping: Repair ktime_get_coarse*() granularity
authorThomas Gleixner <tglx@linutronix.de>
Thu, 13 Jun 2019 19:40:45 +0000 (21:40 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Fri, 14 Jun 2019 09:51:44 +0000 (11:51 +0200)
commit26c03f6e4fed2e2a7acbcdca0e3b9a98af87e6d1
tree5cf1422bf9b708b1402ccd93d6a7edb34d368010
parent665919f774b1123125a915e657e7a3390c6b75ba
timekeeping: Repair ktime_get_coarse*() granularity

Jason reported that the coarse ktime based time getters advance only once
per second and not once per tick as advertised.

The code reads only the monotonic base time, which advances once per
second. The nanoseconds are accumulated on every tick in xtime_nsec up to
a second and the regular time getters take this nanoseconds offset into
account, but the ktime_get_coarse*() implementation fails to do so.

Add the accumulated xtime_nsec value to the monotonic base time to get the
proper per tick advancing coarse tinme.

Fixes: f773cda487c2 ("timekeeping: Add ktime_get_coarse_with_offset")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: Waiman Long <longman@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1906132136280.1791@nanos.tec.linutronix.de
kernel/time/timekeeping.c