Revert "nohz: Fix collision between tick and other hrtimers"
authorLinus Torvalds <torvalds@linux-foundation.org>
Thu, 16 Feb 2017 20:19:18 +0000 (12:19 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 16 Feb 2017 20:19:18 +0000 (12:19 -0800)
commit558e8e27e73f53f8a512485be538b07115fe5f3c
tree7a2f37e7a575537db37ee1238471bbb4f3e0a488
parent4695daefba8df8a11fa0b0edd595eedae9ea59ae
Revert "nohz: Fix collision between tick and other hrtimers"

This reverts commit 24b91e360ef521a2808771633d76ebc68bd5604b and commit
7bdb59f1ad47 ("tick/nohz: Fix possible missing clock reprog after tick
soft restart") that depends on it,

Pavel reports that it causes occasional boot hangs for him that seem to
depend on just how the machine was booted.  In particular, his machine
hangs at around the PCI fixups of the EHCI USB host controller, but only
hangs from cold boot, not from a warm boot.

Thomas Gleixner suspecs it's a CPU hotplug interaction, particularly
since Pavel also saw suspend/resume issues that seem to be related.
We're reverting for now while trying to figure out the root cause.

Reported-bisected-and-tested-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org # reverted commits were marked for stable
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/time/tick-sched.c
kernel/time/tick-sched.h