Thread (84 messages) 84 messages, 6 authors, 2019-03-19

Re: [PATCH v7 03/15] sched/core: uclamp: Add system default clamps

From: Peter Zijlstra <peterz@infradead.org>
Date: 2019-03-13 20:10:24
Also in: linux-pm, lkml

On Wed, Mar 13, 2019 at 05:09:40PM +0000, Patrick Bellasi wrote:
Yes, that should be possible... will look into splitting this out in
v8 to have something like:

---8<---
struct uclamp_req {
	/* Clamp value "requested" by a scheduling entity */
	unsigned int value		: bits_per(SCHED_CAPACITY_SCALE);
	unsigned int bucket_id		: bits_per(UCLAMP_BUCKETS);
	unsigned int active		: 1;
	unsigned int user_defined	: 1;
}

struct uclamp_eff {
	unsigned int value	        : bits_per(SCHED_CAPACITY_SCALE);
	unsigned int bucket_id	        : bits_per(UCLAMP_BUCKETS);
}
No, have _1_ type. There is no point what so ever to splitting this.

Also, what's @user_defined about, I don't think I've seen that in the
parent patch.
struct task_struct {
        // ...
        #ifdef CONFIG_UCLAMP_TASK
                struct uclamp_req uclamp_req[UCLAMP_CNT];
                struct uclamp_eff uclamp_eff[UCLAMP_CNT];
		struct uclamp_se uclamp[UCLAMP_CNT];
		struct uclamp_se uclamp_req[UCLAMP_CNT];

Where the first is the very same introduced in patch #1, and leaving it
in place avoids having to update the sites already using that (or start
#1 with the _eff name to avoid having to change things around?).
        #endif
        // ...
}

static inline struct uclamp_eff
uclamp_eff_get(struct task_struct *p, unsigned int clamp_id)
{
        struct uclamp_eff uc_eff = p->uclamp_eff[clamp_id];
just this ^, these lines seem like a superfluous duplication:
	uc_eff.bucket_id = p->uclamp_req[clamp_id].bucket_id;
	uc_eff.value = p->uclamp_req[clamp_id].value;
	if (unlikely(uc_eff.clamp_value > uclamp_default[clamp_id].value)) {
		uc_eff.clamp_value = uclamp_default[clamp_id].value;
		uc_eff.bucket_id = uclamp_default[clamp_id].bucket_id;
and:

		uc = uclamp_default[clamp_id];
	}

        return uc_eff;
}

static inline void
uclamp_eff_set(struct task_struct *p, unsigned int clamp_id)
{
        p->uclamp_eff[clamp_id] = uclamp_eff_get(p, clamp_id);
}
---8<---

Is that what you mean ?
Getting there :-)
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