On Tue, Sep 13, 2022 at 11:00:36AM +0800, Zhen Lei wrote: > 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 <thunder.leizhen@xxxxxxxxxx> > Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> > Acked-by: Frederic Weisbecker <frederic@xxxxxxxxxx> Looks good, thanks!
