• Thomas Gleixner's avatar
    Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME · a3ed0e43
    Thomas Gleixner authored
    Revert commits
    
    92af4dcb ("tracing: Unify the "boot" and "mono" tracing clocks")
    127bfa5f ("hrtimer: Unify MONOTONIC and BOOTTIME clock behavior")
    7250a404 ("posix-timers: Unify MONOTONIC and BOOTTIME clock behavior")
    d6c7270e ("timekeeping: Remove boot time specific code")
    f2d6fdbf ("Input: Evdev - unify MONOTONIC and BOOTTIME clock behavior")
    d6ed449a ("timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock")
    72199320 ("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: default avatarRafael J. Wysocki <rjw@rjwysocki.net>
    Reported-by: Genki Sky <sky@genki.is>,
    Reported-by: default avatarPavel Machek <pavel@ucw.cz>
    Signed-off-by: default avatarThomas 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>
    a3ed0e43
ftrace.rst 122 KB