sched: Avoid division by zero
sched: Avoid division by zero

Patch a5004278f0525dcb9aa43703ef77bf371ea837cd (sched: Fix
cgroup smp fairness) introduced the possibility of a
divide-by-zero because load-balancing is not synchronized
between sched_domains.

This can cause the state of cpus to change between the first
and second loop over the sched domain in tg_shares_up().

Reported-by: Yinghai Lu <0674548f4d596393408a51d6287a76ebba2f42aa@kernel.org>
Signed-off-by: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Cc: Jes Sorensen <e7bd830ae2d0c840ab7cd2131cd33ff38c069cbe@sgi.com>
Cc: Jens Axboe <165ab144a3ccfd9429d5c6466b275f24fafdb114@oracle.com>
Cc: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>
LKML-Reference: <d1b72bec3991a9f4b979f6c4e607ef97f57ce31b@twins>
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs