Re: [PATCH][v4] x86/resctrl: Add task resctrl information display

[Alexey Dobriyan]

On Fri, Nov 22, 2019 at 05:58:33PM +0800, Chen Yu wrote:
> Monitoring tools that want to find out which resctrl control
> and monitor groups a task belongs to must currently read
> the "tasks" file in every group until they locate the process
> ID.
> 
> Add an additional file /proc/{pid}/resctrl to provide this
> information.

> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c

> +		seq_printf(s, "/%s", rdtg->kn->name);
> +		list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
> +				    mon.crdtgrp_list) {
> +			if (tsk->rmid != crg->mon.rmid)
> +				continue;
> +			seq_printf(s, "%smon_groups/%s",
> +				   rdtg == &rdtgroup_default ? "" : "/",
> +				   crg->kn->name);
> +			break;
> +		}
> +		seq_puts(s, "\n");

This should be seq_putc().


> --- /dev/null
> +++ b/include/linux/resctrl.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _RESCTRL_H
> +#define _RESCTRL_H
> +
> +#ifdef CONFIG_PROC_CPU_RESCTRL
> +
> +#include <linux/proc_fs.h>

Forward declaring stuff should be more than enough.

> +int proc_resctrl_show(struct seq_file *m,
> +		      struct pid_namespace *ns,
> +		      struct pid *pid,
> +		      struct task_struct *tsk);
> +
> +#endif
> +
> +#endif /* _RESCTRL_H */