From: Paul E. McKenney Date: Tue, 9 Nov 2021 19:11:32 +0000 (-0800) Subject: rcu-tasks: Add a ->percpu_enqueue_lim to the rcu_tasks structure X-Git-Tag: block-5.17-2022-01-21~81^2^7~10 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=8dd593fddd630e7dcbe79e98ff5e0d0561e9ff27;p=linux-block.git rcu-tasks: Add a ->percpu_enqueue_lim to the rcu_tasks structure This commit adds a ->percpu_enqueue_lim field to the rcu_tasks structure. This field contains two to the power of the ->percpu_enqueue_shift field, easing construction of iterators over the per-CPU queues that might contain RCU Tasks callbacks. Such iterators will be introduced in later commits. Reported-by: Martin Lau Cc: Neeraj Upadhyay Signed-off-by: Paul E. McKenney --- diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index c11f4e646bf1..608af87a5065 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -52,6 +52,7 @@ struct rcu_tasks_percpu { * @call_func: This flavor's call_rcu()-equivalent function. * @rtpcpu: This flavor's rcu_tasks_percpu structure. * @percpu_enqueue_shift: Shift down CPU ID this much when enqueuing callbacks. + * @percpu_enqueue_lim: Number of per-CPU callback queues in use. * @name: This flavor's textual name. * @kname: This flavor's kthread name. */ @@ -76,6 +77,7 @@ struct rcu_tasks { call_rcu_func_t call_func; struct rcu_tasks_percpu __percpu *rtpcpu; int percpu_enqueue_shift; + int percpu_enqueue_lim; char *name; char *kname; }; @@ -93,6 +95,7 @@ static struct rcu_tasks rt_name = \ .rtpcpu = &rt_name ## __percpu, \ .name = n, \ .percpu_enqueue_shift = ilog2(CONFIG_NR_CPUS), \ + .percpu_enqueue_lim = 1, \ .kname = #rt_name, \ } @@ -172,6 +175,7 @@ static void cblist_init_generic(struct rcu_tasks *rtp) raw_spin_lock_irqsave(&rtp->cbs_gbl_lock, flags); rtp->percpu_enqueue_shift = ilog2(nr_cpu_ids); + rtp->percpu_enqueue_lim = 1; for_each_possible_cpu(cpu) { struct rcu_tasks_percpu *rtpcp = per_cpu_ptr(rtp->rtpcpu, cpu);