nohz: Fix !HIGH_RES_TIMERS hang

Simon Horman reported this crash on a system with
high-res timers disabled but nohz enabled:

  > ------------[ cut here ]------------
  > kernel BUG at kernel/irq_work.c:135!

    BUG_ON(!irqs_disabled());

So something enabled interrupts in the periodic tick handling machinery,
and that code path indeed has a local_irq_disable()/enable pair in
tick_nohz_switch_to_nohz() which causes havoc. Fix it.

This patch also fixes a +nohz -hrtimers hang reported by Ingo Molnar.

Reported-by: Simon Horman <[email protected]>
Reported-by: Ingo Molnar <[email protected]>
Tested-by: Simon Horman <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: LAK <[email protected]>
Cc: Magnus Damm <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1505071425520.4225@nanos
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions