[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <YsK2riNersXeRgKM@hirez.programming.kicks-ass.net>
Date: Mon, 4 Jul 2022 11:45:18 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Cruz Zhao <CruzZhao@...ux.alibaba.com>
Cc: mingo@...hat.com, juri.lelli@...hat.com,
vincent.guittot@...aro.org, dietmar.eggemann@....com,
rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
bristot@...hat.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] sched/core: Introduce nr_running percpu for each
cookie
On Tue, Jun 28, 2022 at 03:57:24PM +0800, Cruz Zhao wrote:
> static unsigned long sched_core_alloc_cookie(void)
> {
> struct sched_core_cookie *ck = kmalloc(sizeof(*ck), GFP_KERNEL);
> + int cpu;
> +
> if (!ck)
> return 0;
>
> refcount_set(&ck->refcnt, 1);
> +
> + ck->nr_running = alloc_percpu(unsigned int);
if (!ck->nr_running)
// do something
> + for_each_possible_cpu(cpu)
> + *per_cpu_ptr(ck->nr_running, cpu) = 0;
So I really, as in *really* dislike how this blows up the size of
cookies. Esp. with 100s of CPUs not actually being rare these days.
Powered by blists - more mailing lists