Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4ffa3c97 authored by Jiri Olsa's avatar Jiri Olsa Committed by Thomas Gleixner
Browse files

x86/intel_rdt: Add cpus_list rdtgroup file 



The resource control filesystem provides only a bitmask based cpus file for
assigning CPUs to a resource group. That's cumbersome with large cpumasks
and non-intuitive when modifying the file from the command line.

Range based cpu lists are commonly used along with bitmask based cpu files
in various subsystems throughout the kernel.

Add 'cpus_list' file which is CPU range based.

  # cd /sys/fs/resctrl/
  # echo 1-10 > krava/cpus_list
  # cat krava/cpus_list
  1-10
  # cat krava/cpus
  0007fe
  # cat cpus
  fffff9
  # cat cpus_list
  0,3-23

[ tglx: Massaged changelog and replaced "bitmask lists" by "CPU ranges" ]

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20170410145232.GF25354@krava


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 17f8ba1d

Documentation/x86/intel_rdt_ui.txt

+3 −0
Original line number Diff line number Diff line
@@ -59,6 +59,9 @@ There are three files associated with each group: 
	given to the default (root) group. You cannot remove CPUs

	from the default group.



"cpus_list": One or more CPU ranges of logical CPUs assigned to this

	     group. Same rules apply like for the "cpus" file.



"schemata": A list of all the resources available to this group.

	Each resource has its own line and format - see below for

	details.

arch/x86/include/asm/intel_rdt.h

+5 −0
Original line number Diff line number Diff line
@@ -37,6 +37,9 @@ struct rdtgroup { 
/* rdtgroup.flags */

#define	RDT_DELETED		1



/* rftype.flags */

#define RFTYPE_FLAGS_CPUS_LIST	1



/* List of all resource groups */

extern struct list_head rdt_all_groups;
@@ -49,6 +52,7 @@ int __init rdtgroup_init(void); 
 * @name:	File name

 * @mode:	Access mode

 * @kf_ops:	File operations

 * @flags:	File specific RFTYPE_FLAGS_* flags

 * @seq_show:	Show content of the file

 * @write:	Write to the file

 */
@@ -56,6 +60,7 @@ struct rftype { 
	char			*name;

	umode_t			mode;

	struct kernfs_ops	*kf_ops;

	unsigned long		flags;



	int (*seq_show)(struct kernfs_open_file *of,

			struct seq_file *sf, void *v);

arch/x86/kernel/cpu/intel_rdt_rdtgroup.c

+25 −4
Original line number Diff line number Diff line
@@ -174,6 +174,13 @@ static struct kernfs_ops rdtgroup_kf_single_ops = { 
	.seq_show		= rdtgroup_seqfile_show,

};



static bool is_cpu_list(struct kernfs_open_file *of)

{

	struct rftype *rft = of->kn->priv;



	return rft->flags & RFTYPE_FLAGS_CPUS_LIST;

}



static int rdtgroup_cpus_show(struct kernfs_open_file *of,

			      struct seq_file *s, void *v)

{
@@ -182,10 +189,12 @@ static int rdtgroup_cpus_show(struct kernfs_open_file *of, 


	rdtgrp = rdtgroup_kn_lock_live(of->kn);



	if (rdtgrp)

		seq_printf(s, "%*pb\n", cpumask_pr_args(&rdtgrp->cpu_mask));

	else

	if (rdtgrp) {

		seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",

			   cpumask_pr_args(&rdtgrp->cpu_mask));

	} else {

		ret = -ENOENT;

	}

	rdtgroup_kn_unlock(of->kn);



	return ret;
@@ -252,7 +261,11 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, 
		goto unlock;

	}



	if (is_cpu_list(of))

		ret = cpulist_parse(buf, newmask);

	else

		ret = cpumask_parse(buf, newmask);



	if (ret)

		goto unlock;
@@ -472,6 +485,14 @@ static struct rftype rdtgroup_base_files[] = { 
		.write		= rdtgroup_cpus_write,

		.seq_show	= rdtgroup_cpus_show,

	},

	{

		.name		= "cpus_list",

		.mode		= 0644,

		.kf_ops		= &rdtgroup_kf_single_ops,

		.write		= rdtgroup_cpus_write,

		.seq_show	= rdtgroup_cpus_show,

		.flags		= RFTYPE_FLAGS_CPUS_LIST,

	},

	{

		.name		= "tasks",

		.mode		= 0644,