[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAB8ipk_w9JeFmbjSOFR-GnaPNiAoFt8f30Oxh3fZRw58wDXo4w@mail.gmail.com>
Date: Tue, 8 Jun 2021 23:01:59 +0800
From: Xuewen Yan <xuewen.yan94@...il.com>
To: Qais Yousef <qais.yousef@....com>
Cc: Quentin Perret <qperret@...gle.com>,
Ingo Molnar <mingo@...hat.com>,
Peter Zijlstra <peterz@...radead.org>,
Juri Lelli <juri.lelli@...hat.com>,
Vincent Guittot <vincent.guittot@...aro.org>,
Dietmar Eggemann <dietmar.eggemann@....com>,
Steven Rostedt <rostedt@...dmis.org>,
Benjamin Segall <bsegall@...gle.com>,
Mel Gorman <mgorman@...e.de>,
Daniel Bristot de Oliveira <bristot@...hat.com>,
linux-kernel <linux-kernel@...r.kernel.org>,
Chunyan Zhang <zhang.lyra@...il.com>,
Ryan Y <xuewyan@...mail.com>,
Patrick Bellasi <patrick.bellasi@...bug.net>, tj@...nel.org
Subject: Re: [PATCH] sched/uclamp: Avoid setting cpu.uclamp.min bigger than cpu.uclamp.max
Hi
On Tue, Jun 8, 2021 at 10:25 PM Qais Yousef <qais.yousef@....com> wrote:
>
> --->8---
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 9e9a5be35cde..1d2d3e6648a6 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1403,38 +1403,28 @@ static void uclamp_sync_util_min_rt_default(void)
> static inline struct uclamp_se
> uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id)
> {
> - struct uclamp_se uc_req = p->uclamp_req[clamp_id];
> + /* Copy by value as we could modify it */
> + struct uclamp_se uc_eff = p->uclamp_req[clamp_id];
> #ifdef CONFIG_UCLAMP_TASK_GROUP
> + unsigned long tg_min, tg_max, value;
>
> /*
> * Tasks in autogroups or root task group will be
> * restricted by system defaults.
> */
> if (task_group_is_autogroup(task_group(p)))
> - return uc_req;
> + return uc_eff;
> if (task_group(p) == &root_task_group)
> - return uc_req;
> + return uc_eff;
>
> - switch (clamp_id) {
> - case UCLAMP_MIN: {
> - struct uclamp_se uc_min = task_group(p)->uclamp[clamp_id];
> - if (uc_req.value < uc_min.value)
> - return uc_min;
> - break;
> - }
> - case UCLAMP_MAX: {
> - struct uclamp_se uc_max = task_group(p)->uclamp[clamp_id];
> - if (uc_req.value > uc_max.value)
> - return uc_max;
> - break;
> - }
> - default:
> - WARN_ON_ONCE(1);
> - break;
> - }
> + tg_min = task_group(p)->uclamp[UCLAMP_MIN].value;
> + tg_max = task_group(p)->uclamp[UCLAMP_MAX].value;
> + value = uc_eff.value;
> + value = clamp(value, tg_min, tg_max);
> + uclamp_se_set(&uc_eff, value, false);
Is it reasonable to set user_defined to be false here?
> #endif
>
> - return uc_req;
> + return uc_eff;
> }
>
> /*
> @@ -1661,8 +1651,7 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
>
> #ifdef CONFIG_UCLAMP_TASK_GROUP
> static inline void
> -uclamp_update_active_tasks(struct cgroup_subsys_state *css,
> - unsigned int clamps)
> +uclamp_update_active_tasks(struct cgroup_subsys_state *css)
> {
> enum uclamp_id clamp_id;
> struct css_task_iter it;
> @@ -1670,10 +1659,8 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
>
> css_task_iter_start(css, 0, &it);
> while ((p = css_task_iter_next(&it))) {
> - for_each_clamp_id(clamp_id) {
> - if ((0x1 << clamp_id) & clamps)
> - uclamp_update_active(p, clamp_id);
> - }
> + for_each_clamp_id(clamp_id)
> + uclamp_update_active(p, clamp_id);
> }
> css_task_iter_end(&it);
> }
> @@ -9626,7 +9613,7 @@ static void cpu_util_update_eff(struct cgroup_subsys_state *css)
> }
>
> /* Immediately update descendants RUNNABLE tasks */
> - uclamp_update_active_tasks(css, clamps);
> + uclamp_update_active_tasks(css);
> }
> }
Would you resend another email? maybe it would be better to resend an
email with a new subject?
BR
xuewen
Powered by blists - more mailing lists