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Groups > linux.kernel > #1399387
| From | Peter Zijlstra <peterz@infradead.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared |
| Date | 2016-05-11 19:40 +0200 |
| Message-ID | <rxGh4-4oy-17@gated-at.bofh.it> (permalink) |
| References | <rwR4S-3QS-9@gated-at.bofh.it> <rwR4T-3QS-23@gated-at.bofh.it> <rxAY1-7z7-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, May 11, 2016 at 12:55:56PM +0100, Matt Fleming wrote:
> This breaks my POWER7 box which presumably doesn't have SD_SHARE_PKG_RESOURCES,
> index 978b3ef2d87e..d27153adee4d 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -7920,7 +7920,8 @@ static inline void set_cpu_sd_state_busy(void)
> goto unlock;
> sd->nohz_idle = 0;
>
> - atomic_inc(&sd->shared->nr_busy_cpus);
> + if (sd->shared)
> + atomic_inc(&sd->shared->nr_busy_cpus);
> unlock:
> rcu_read_unlock();
> }
Ah, no, the problem is that while it does have SHARE_PKG_RESOURCES (in
its SMT domain -- SMT threads share all cache after all), I failed to
connect the sched_domain_shared structure for it.
Does something like this also work?
---
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6389,10 +6389,6 @@ sd_init(struct sched_domain_topology_lev
sd->cache_nice_tries = 1;
sd->busy_idx = 2;
- sd->shared = *per_cpu_ptr(sdd->sds, sd_id);
- atomic_inc(&sd->shared->ref);
- atomic_set(&sd->shared->nr_busy_cpus, sd_weight);
-
#ifdef CONFIG_NUMA
} else if (sd->flags & SD_NUMA) {
sd->cache_nice_tries = 2;
@@ -6414,6 +6410,16 @@ sd_init(struct sched_domain_topology_lev
sd->idle_idx = 1;
}
+ /*
+ * For all levels sharing cache; connect a sched_domain_shared
+ * instance.
+ */
+ if (sd->flags & SH_SHARED_PKG_RESOURCES) {
+ sd->shared = *per_cpu_ptr(sdd->sds, sd_id);
+ atomic_inc(&sd->shared->ref);
+ atomic_set(&sd->shared->nr_busy_cpus, sd_weight);
+ }
+
sd->private = sdd;
return sd;
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[RFC][PATCH 0/7] sched: select_idle_siblings rewrite Peter Zijlstra <peterz@infradead.org> - 2016-05-09 13:00 +0200
[RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Peter Zijlstra <peterz@infradead.org> - 2016-05-09 13:00 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Matt Fleming <matt@codeblueprint.co.uk> - 2016-05-11 14:00 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Peter Zijlstra <peterz@infradead.org> - 2016-05-11 14:40 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Peter Zijlstra <peterz@infradead.org> - 2016-05-11 20:20 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Peter Zijlstra <peterz@infradead.org> - 2016-05-11 20:30 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Michael Neuling <mikey@neuling.org> - 2016-05-12 04:10 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Peter Zijlstra <peterz@infradead.org> - 2016-05-12 07:10 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Michael Neuling <mikey@neuling.org> - 2016-05-12 13:10 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Peter Zijlstra <peterz@infradead.org> - 2016-05-12 13:40 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Peter Zijlstra <peterz@infradead.org> - 2016-05-11 19:40 +0200
Re: [RFC][PATCH 4/7] sched: Replace sd_busy/nr_busy_cpus with sched_domain_shared Matt Fleming <matt@codeblueprint.co.uk> - 2016-05-11 20:10 +0200
[RFC][PATCH 1/7] sched: Remove unused @cpu argument from destroy_sched_domain*() Peter Zijlstra <peterz@infradead.org> - 2016-05-09 13:00 +0200
[RFC][PATCH 3/7] sched: Introduce struct sched_domain_shared Peter Zijlstra <peterz@infradead.org> - 2016-05-09 13:00 +0200
[RFC][PATCH 6/7] sched: Optimize SCHED_SMT Peter Zijlstra <peterz@infradead.org> - 2016-05-09 13:00 +0200
Re: [RFC][PATCH 0/7] sched: select_idle_siblings rewrite Chris Mason <clm@fb.com> - 2016-05-10 03:00 +0200
Re: [RFC][PATCH 0/7] sched: select_idle_siblings rewrite Chris Mason <clm@fb.com> - 2016-05-11 16:30 +0200
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