From: Peter Zijlstra <pet...@infradead.org> There is no point in doing a call_rcu() for each domain, only do a callback for the root sched domain and clean up the entire set in one go.
Also make the entire call chain be called destroy_sched_domain*() to remove confusion with the free_sched_domains() call, which does an entirely different thing. Both cpu_attach_domain() callers of destroy_sched_domain() can live without the call_rcu() because at those points the sched_domain hasn't been published yet. This one seems to work much better; so much for last minute 'cleanups'. --- kernel/sched/core.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ab6e6cf..c4596e0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5833,10 +5833,8 @@ static void free_sched_groups(struct sched_group *sg, int free_sgc) } while (sg != first); } -static void free_sched_domain(struct rcu_head *rcu) +static void destroy_sched_domain(struct sched_domain *sd) { - struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); - /* * If its an overlapping domain it has private groups, iterate and * nuke them all. @@ -5850,15 +5848,21 @@ static void free_sched_domain(struct rcu_head *rcu) kfree(sd); } -static void destroy_sched_domain(struct sched_domain *sd) +static void destroy_sched_domains_rcu(struct rcu_head *rcu) { - call_rcu(&sd->rcu, free_sched_domain); + struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); + + while (sd) { + struct sched_domain *parent = sd->parent; + destroy_sched_domain(sd); + sd = parent; + } } static void destroy_sched_domains(struct sched_domain *sd) { - for (; sd; sd = sd->parent) - destroy_sched_domain(sd); + if (sd) + call_rcu(&sd->rcu, destroy_sched_domains_rcu); } /* -- 1.7.9.5