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Date:   Thu, 5 Oct 2023 16:42:57 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Youssef Esmat <youssefesmat@chromium.org>
Cc:     Daniel Jordan <daniel.m.jordan@oracle.com>, mingo@kernel.org,
        vincent.guittot@linaro.org, linux-kernel@vger.kernel.org,
        juri.lelli@redhat.com, dietmar.eggemann@arm.com,
        rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
        bristot@redhat.com, corbet@lwn.net, qyousef@layalina.io,
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        pavel@ucw.cz, qperret@google.com, tim.c.chen@linux.intel.com,
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        yu.c.chen@intel.com, joel@joelfernandes.org, efault@gmx.de,
        tglx@linutronix.de
Subject: Re: [PATCH 00/15] sched: EEVDF and latency-nice and/or slice-attr
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On Thu, Oct 05, 2023 at 04:14:08PM +0200, Peter Zijlstra wrote:

> --- eevdf.c.orig	2023-10-05 16:11:35.821114320 +0200
> +++ eevdf.c	2023-10-05 16:08:38.387080327 +0200
> @@ -7,6 +7,7 @@
>  #include <sys/param.h>
>  
>  bool eligible = true;
> +bool bias = false;
>  unsigned long V_lim = 20;
>  
>  struct entity {
> @@ -79,16 +80,17 @@
>  
>  struct entity *pick_entity(int nr, struct entity *es)
>  {
> -	unsigned long W = 0, V = 0;
> +	unsigned long W = 0, V = 0, R = 0;
>  	struct entity *e = NULL;
>  
>  	for (int i = 0; i < nr; i++) {
>  		V += es[i].weight * es[i].vruntime;
> +		R += es[i].request;

				* 1024

Also, average seems too much, one large value lifts it too easily. 

Need to come up with something better :/

>  		W += es[i].weight;
>  	}
>  
>  	for (int i = 0; i < nr; i++) {
> -		if (eligible && W*es[i].vruntime > V)
> +		if (eligible && W*es[i].vruntime > V + (bias * R))
>  			continue;
>  
>  		if (!e || es[i].vdeadline < e->vdeadline)
> @@ -169,10 +171,14 @@
>  
>  	const int N = sizeof(es) / sizeof(es[0]);
>  
> -	while ((opt = getopt(argc, argv, "nv:e:")) != -1) {
> +	while ((opt = getopt(argc, argv, "bnv:e:")) != -1) {
>  		unsigned int v,w,r;
>  
>  		switch (opt) {
> +		case 'b':
> +			bias = true;
> +			break;
> +
>  		case 'n':
>  			eligible = false;
>  			break;