On Mon, May 09, 2016 at 12:48:09PM +0200, Peter Zijlstra wrote:
> 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.
>
> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
> ---
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(-)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5824,10 +5824,8 @@ static void free_sched_groups(struct sch
} 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.
@@ -5841,15 +5839,21 @@ static void free_sched_domain(struct 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);
}
/*
