On 16/08/2026 20:10, Tejun Heo wrote:
(cc'ing Breno as he has been working in the area)
Hello,
Sorry about the delay.
Same here so no worries, summer holidays.. :)
On Tue, Aug 04, 2026 at 11:19:24AM +0100, Tvrtko Ursulin wrote:
struct workqueue_attrs {
/**
- * @nice: nice level
+ * @prio: priority level
+ */
+ enum wq_priority prio;
+
+ /**
+ * @nice: nice level for WQ_PRIO_HIGH
*/
int nice;
I find this rather confusing. We're scattering the same internal state
across multiple fields. If you look at scheduler code, rt and normal nice
values are encoded into a single prio value, maybe we can do the same?
I thought it was more elegant to split the policy from the priority
within a policy for call sites which only look up the policy. I can
change it to encode all in a single integer or something. Alternative
will be to call some helpers here and there which answers the "is this a
rt policy" based on a range checks. At which point it felt one word in
the struct is nicer than conditionals across the code. Your call what
you prefer.
static int alloc_and_link_pwqs(struct workqueue_struct *wq)
{
- bool highpri = wq->flags & WQ_HIGHPRI;
- int cpu, ret;
+ int prio, cpu, ret;
lockdep_assert_held(&wq_pool_mutex);
+ if (wq->flags & WQ_RTPRI)
+ prio = WQ_PRIO_RT;
+ else if (wq->flags & WQ_HIGHPRI)
+ prio = WQ_PRIO_HIGH;
+ else
+ prio = WQ_PRIO_NORMAL;
+
wq->cpu_pwq = alloc_percpu(struct pool_workqueue *);
if (!wq->cpu_pwq)
goto enomem;
@@ -5622,7 +5637,7 @@ static int alloc_and_link_pwqs(struct workqueue_struct
*wq)
struct pool_workqueue **pwq_p;
struct worker_pool *pool;
- pool = &(per_cpu_ptr(pools, cpu)[highpri]);
+ pool = &(per_cpu_ptr(pools, cpu)[prio]);
And this looks a bit confusing too because there's no per-cpu counterpart
but it looks like there should be.
I did not quite manage to follow you here. Was this not the per cpu
part, with unbound and ordered down lower? You have to excuse me I am
new in this code.
I wonder whether this would look better after the percpu and unbound pool
unification that Breno is working on.
I suppose this landed by now? I can see some changes so once we clarify
the above opens I will rebase and adjust.
Regards,
Tvrtko
