On Fri, Jun 5, 2020 at 12:12 PM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: > > Paolo Bonzini <pbonzini@xxxxxxxxxx> writes: > > On 04/06/20 21:28, Miklos Szeredi wrote: > >> time(2) returns good time, while clock_gettime(2) returns bad time. > >> Here's an example: > >> > >> time=1591298725 RT=1591300383 MONO=39582 MONO_RAW=39582 BOOT=39582 > >> time=1591298726 RT=1591300383 MONO=39582 MONO_RAW=39582 BOOT=39582 > >> time=1591298727 RT=1591300383 MONO=39582 MONO_RAW=39582 BOOT=39582 > >> time=1591298728 RT=1591300383 MONO=39582 MONO_RAW=39582 BOOT=39582 > >> time=1591298729 RT=1591300383 MONO=39582 MONO_RAW=39582 BOOT=39582 > >> > >> As you can see, only time(2) is updated, the others remain the same. > >> date(1) uses clock_gettime(CLOCK_REALTIME) so that shows the bad date. > >> > >> When the correct time reaches the value returned by CLOCK_REALTIME, > >> the value jumps exactly 2199 seconds. > > Which value jumps? The time value returned by clock_gettime() and gettimeofday() jumps by 2199s after the resume of host, and then again and again jumps with a period of 2^41 ns. Only time() returns the correct value and that appears to use the VDSO since there's no time() syscall in strace. > I can actually now reproduce, but I won't be able to investigate that > before monday. No problem. Good news that you can reproduce it now. Thanks, Miklos
