From 7ee880b7bf1dea88d0a472b775aebdb4fb6bf860 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Wed, 15 Apr 2020 22:26:55 +0000 Subject: rcu: Initialize and destroy rcu_synchronize only when necessary The __wait_rcu_gp() function unconditionally initializes and cleans up each element of rs_array[], whether used or not. This is slightly wasteful and rather confusing, so this commit skips both initialization and cleanup for duplicate callback functions. Signed-off-by: Wei Yang Signed-off-by: Paul E. McKenney --- kernel/rcu/update.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 84843adfd939..f5a82e107bcb 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -390,13 +390,14 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, might_sleep(); continue; } - init_rcu_head_on_stack(&rs_array[i].head); - init_completion(&rs_array[i].completion); for (j = 0; j < i; j++) if (crcu_array[j] == crcu_array[i]) break; - if (j == i) + if (j == i) { + init_rcu_head_on_stack(&rs_array[i].head); + init_completion(&rs_array[i].completion); (crcu_array[i])(&rs_array[i].head, wakeme_after_rcu); + } } /* Wait for all callbacks to be invoked. */ @@ -407,9 +408,10 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array, for (j = 0; j < i; j++) if (crcu_array[j] == crcu_array[i]) break; - if (j == i) + if (j == i) { wait_for_completion(&rs_array[i].completion); - destroy_rcu_head_on_stack(&rs_array[i].head); + destroy_rcu_head_on_stack(&rs_array[i].head); + } } } EXPORT_SYMBOL_GPL(__wait_rcu_gp); -- cgit v1.2.3-58-ga151