rcu: Simplify rcu_init_nohz() cpumask handling

In kernels built with either CONFIG_RCU_NOCB_CPU_DEFAULT_ALL=y or
CONFIG_NO_HZ_FULL=y, additional CPUs must be added to rcu_nocb_mask.
Except that kernels booted without the rcu_nocbs= will not have
allocated rcu_nocb_mask.  And the current rcu_init_nohz() function uses
its need_rcu_nocb_mask and offload_all local variables to track the
rcu_nocb and nohz_full state.

But there is a much simpler approach, namely creating a cpumask pointer
to track the default and then using cpumask_available() to check the
rcu_nocb_mask state.  This commit takes this approach, thereby simplifying
and shortening the rcu_init_nohz() function.

Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Joel Fernandes (Google) <[email protected]>
Acked-by: Frederic Weisbecker <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

0 files changed, 0 insertions, 0 deletions