nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off
authorThomas Gleixner <tglx@linutronix.de>
Fri, 29 Nov 2013 11:18:13 +0000 (12:18 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 26 Jun 2014 19:12:41 +0000 (15:12 -0400)
commitec804bd9e1ecad7a6d9f9428eaf388e3dac9cb63
tree5c847b8f464893a1016aa34d3536f538d7b177ca
parentfeaad01723471c67e10f5c5bc537299e686f78b8
nohz: Fix another inconsistency between CONFIG_NO_HZ=n and nohz=off

commit 0e576acbc1d9600cf2d9b4a141a2554639959d50 upstream.

If CONFIG_NO_HZ=n tick_nohz_get_sleep_length() returns NSEC_PER_SEC/HZ.

If CONFIG_NO_HZ=y and the nohz functionality is disabled via the
command line option "nohz=off" or not enabled due to missing hardware
support, then tick_nohz_get_sleep_length() returns 0. That happens
because ts->sleep_length is never set in that case.

Set it to NSEC_PER_SEC/HZ when the NOHZ mode is inactive.

Reported-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/time/tick-sched.c