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| author | Frederic Weisbecker <frederic@kernel.org> | 2024-01-12 18:46:19 +0300 |
|---|---|---|
| committer | Boqun Feng <boqun.feng@gmail.com> | 2024-02-14 18:51:36 +0300 |
| commit | 8e5e621566485a3e160c0d8bfba206cb1d6b980d (patch) | |
| tree | ac9a02f263304cd2e7ce2e6a39a7f6bd87718517 /kernel/rcu/tree_exp.h | |
| parent | c19e5d3b497a3036f800edf751dc7814e3e887e1 (diff) | |
| download | linux-8e5e621566485a3e160c0d8bfba206cb1d6b980d.tar.xz | |
rcu/exp: Make parallel exp gp kworker per rcu node
When CONFIG_RCU_EXP_KTHREAD=n, the expedited grace period per node
initialization is performed in parallel via workqueues (one work per
node).
However in CONFIG_RCU_EXP_KTHREAD=y, this per node initialization is
performed by a single kworker serializing each node initialization (one
work for all nodes).
The second part is certainly less scalable and efficient beyond a single
leaf node.
To improve this, expand this single kworker into per-node kworkers. This
new layout is eventually intended to remove the workqueues based
implementation since it will essentially now become duplicate code.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Diffstat (limited to 'kernel/rcu/tree_exp.h')
| -rw-r--r-- | kernel/rcu/tree_exp.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 6123a60d9a4d..0318a8a062d5 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -432,9 +432,9 @@ static inline bool rcu_exp_worker_started(void) return !!READ_ONCE(rcu_exp_gp_kworker); } -static inline bool rcu_exp_par_worker_started(void) +static inline bool rcu_exp_par_worker_started(struct rcu_node *rnp) { - return !!READ_ONCE(rcu_exp_par_gp_kworker); + return !!READ_ONCE(rnp->exp_kworker); } static inline void sync_rcu_exp_select_cpus_queue_work(struct rcu_node *rnp) @@ -445,7 +445,7 @@ static inline void sync_rcu_exp_select_cpus_queue_work(struct rcu_node *rnp) * another work item on the same kthread worker can result in * deadlock. */ - kthread_queue_work(rcu_exp_par_gp_kworker, &rnp->rew.rew_work); + kthread_queue_work(READ_ONCE(rnp->exp_kworker), &rnp->rew.rew_work); } static inline void sync_rcu_exp_select_cpus_flush_work(struct rcu_node *rnp) @@ -487,7 +487,7 @@ static inline bool rcu_exp_worker_started(void) return !!READ_ONCE(rcu_gp_wq); } -static inline bool rcu_exp_par_worker_started(void) +static inline bool rcu_exp_par_worker_started(struct rcu_node *rnp) { return !!READ_ONCE(rcu_par_gp_wq); } @@ -550,7 +550,7 @@ static void sync_rcu_exp_select_cpus(void) rnp->exp_need_flush = false; if (!READ_ONCE(rnp->expmask)) continue; /* Avoid early boot non-existent wq. */ - if (!rcu_exp_par_worker_started() || + if (!rcu_exp_par_worker_started(rnp) || rcu_scheduler_active != RCU_SCHEDULER_RUNNING || rcu_is_last_leaf_node(rnp)) { /* No worker started yet or last leaf, do direct call. */ |