linux/Documentation/trace
Thomas Gleixner a3ed0e4393 Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME
Revert commits

92af4dcb4e ("tracing: Unify the "boot" and "mono" tracing clocks")
127bfa5f43 ("hrtimer: Unify MONOTONIC and BOOTTIME clock behavior")
7250a4047a ("posix-timers: Unify MONOTONIC and BOOTTIME clock behavior")
d6c7270e91 ("timekeeping: Remove boot time specific code")
f2d6fdbfd2 ("Input: Evdev - unify MONOTONIC and BOOTTIME clock behavior")
d6ed449afd ("timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock")
72199320d4 ("timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock")

As stated in the pull request for the unification of CLOCK_MONOTONIC and
CLOCK_BOOTTIME, it was clear that we might have to revert the change.

As reported by several folks systemd and other applications rely on the
documented behaviour of CLOCK_MONOTONIC on Linux and break with the above
changes. After resume daemons time out and other timeout related issues are
observed. Rafael compiled this list:

* systemd kills daemons on resume, after >WatchdogSec seconds
  of suspending (Genki Sky).  [Verified that that's because systemd uses
  CLOCK_MONOTONIC and expects it to not include the suspend time.]

* systemd-journald misbehaves after resume:
  systemd-journald[7266]: File /var/log/journal/016627c3c4784cd4812d4b7e96a34226/system.journal
corrupted or uncleanly shut down, renaming and replacing.
  (Mike Galbraith).

* NetworkManager reports "networking disabled" and networking is broken
  after resume 50% of the time (Pavel).  [May be because of systemd.]

* MATE desktop dims the display and starts the screensaver right after
  system resume (Pavel).

* Full system hang during resume (me).  [May be due to systemd or NM or both.]

That happens on debian and open suse systems.

It's sad, that these problems were neither catched in -next nor by those
folks who expressed interest in this change.

Reported-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Reported-by: Genki Sky <sky@genki.is>,
Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
2018-04-26 14:53:32 +02:00
..
postprocess mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory 2018-04-05 21:36:27 -07:00
coresight-cpu-debug.txt doc: coresight: correct usage for disabling idle states 2017-10-20 15:03:06 +02:00
coresight.txt coresight: Update documentation for perf usage 2018-02-16 14:55:46 -03:00
events-kmem.rst trace doc: convert trace/events-kmem.txt to rst format 2018-03-07 10:25:54 -07:00
events-msr.rst trace doc: convert trace/events-msr.txt to rst format 2018-03-07 10:26:06 -07:00
events-nmi.rst trace doc: convert trace/events-nmi.txt to rst format 2018-03-07 10:26:02 -07:00
events-power.rst trace doc: convert trace/events-power.txt to rst format 2018-03-07 10:25:59 -07:00
events.rst New features: 2018-04-10 11:27:30 -07:00
ftrace-design.rst trace doc: convert trace/ftrace-design.txt to rst format 2018-03-07 10:22:57 -07:00
ftrace-uses.rst trace doc: add ftrace-uses.rst to doc tree 2018-03-07 10:23:01 -07:00
ftrace.rst Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +02:00
function-graph-fold.vim tracing: Add vim script to enable folding for function_graph traces 2009-08-26 00:32:04 -04:00
histogram.txt tracing: Add a clock attribute for hist triggers 2018-03-10 16:06:03 -05:00
hwlat_detector.rst trace doc: convert trace/hwlat_detector.txt to rst fromat 2018-03-07 10:26:14 -07:00
index.rst trace doc: convert trace/stm.txt to rst format 2018-03-07 10:26:22 -07:00
intel_th.rst trace doc: convert trace/intel_th.txt to rst format 2018-03-07 10:26:18 -07:00
kprobetrace.rst trace doc: convert trace/kprobetrace.txt to rst format 2018-03-07 10:23:15 -07:00
mmiotrace.rst trace doc: convert trace/mmiotrace.txt to rst format 2018-03-07 10:26:10 -07:00
ring-buffer-design.txt doc: fix double words 2014-03-21 13:16:58 +01:00
stm.rst trace doc: convert trace/stm.txt to rst format 2018-03-07 10:26:22 -07:00
tracepoint-analysis.rst trace doc: convert trace/tracepoint-analysis.txt to rst format 2018-03-07 10:23:06 -07:00
tracepoints.rst trace doc: convert trace/tracepoints.txt to rst format 2018-03-07 10:23:23 -07:00
uprobetracer.rst trace doc: convert trace/uprobetracer.txt to rst format 2018-03-07 10:23:19 -07:00