[PATCH] x86/intel_rdt: Add cpus_list rdtgroup file

From: Jiri Olsa
Date: Wed Mar 29 2017 - 11:10:03 EST

While playing with the resctrl interface I found it much
easier to deal with cpumask list rather than just regular
cpumask.

Adding cpus_list file to provide cpumask list interface
to define group's cpus.

# 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

Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Shaohua Li <shli@xxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
arch/x86/include/asm/intel_rdt.h | 16 +++++++++---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 42 +++++++++++++++++++++++---------
arch/x86/kernel/cpu/intel_rdt_schemata.c | 6 +++--
3 files changed, 47 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h
index 0d64397cee58..0e74e58e1f23 100644
--- a/arch/x86/include/asm/intel_rdt.h
+++ b/arch/x86/include/asm/intel_rdt.h
@@ -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;

@@ -54,16 +57,19 @@ 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);
+ struct seq_file *sf, void *v,
+ unsigned long flags);
/*
* write() is the generic write callback which maps directly to
* kernfs write operation and overrides all other operations.
* Maximum write size is determined by ->max_write_len.
*/
ssize_t (*write)(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off);
+ char *buf, size_t nbytes, loff_t off,
+ unsigned long flags);
};

/**
@@ -179,9 +185,11 @@ void rdt_cbm_update(void *arg);
struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn);
void rdtgroup_kn_unlock(struct kernfs_node *kn);
ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off);
+ char *buf, size_t nbytes, loff_t off,
+ unsigned long flags);
int rdtgroup_schemata_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v);
+ struct seq_file *s, void *v,
+ unsigned long flags);

/*
* intel_rdt_sched_in() - Writes the task's CLOSid to IA32_PQR_MSR
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 9ac2a5cdd9c2..3a1dfb421dc5 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -153,7 +153,7 @@ static int rdtgroup_seqfile_show(struct seq_file *m, void *arg)
struct rftype *rft = of->kn->priv;

if (rft->seq_show)
- return rft->seq_show(of, m, arg);
+ return rft->seq_show(of, m, arg, rft->flags);
return 0;
}

@@ -163,7 +163,7 @@ static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf,
struct rftype *rft = of->kn->priv;

if (rft->write)
- return rft->write(of, buf, nbytes, off);
+ return rft->write(of, buf, nbytes, off, rft->flags);

return -EINVAL;
}
@@ -175,15 +175,17 @@ static struct kernfs_ops rdtgroup_kf_single_ops = {
};

static int rdtgroup_cpus_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
+ struct seq_file *s, void *v,
+ unsigned long flags)
{
+ const char *fmt = flags & RFTYPE_FLAGS_CPUS_LIST ? "%*pbl\n" : "%*pb\n";
struct rdtgroup *rdtgrp;
int ret = 0;

rdtgrp = rdtgroup_kn_lock_live(of->kn);

if (rdtgrp)
- seq_printf(s, "%*pb\n", cpumask_pr_args(&rdtgrp->cpu_mask));
+ seq_printf(s, fmt, cpumask_pr_args(&rdtgrp->cpu_mask));
else
ret = -ENOENT;
rdtgroup_kn_unlock(of->kn);
@@ -230,7 +232,8 @@ rdt_update_closid(const struct cpumask *cpu_mask, int *closid)
}

static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
+ char *buf, size_t nbytes, loff_t off,
+ unsigned long flags)
{
cpumask_var_t tmpmask, newmask;
struct rdtgroup *rdtgrp, *r;
@@ -252,7 +255,11 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
goto unlock;
}

- ret = cpumask_parse(buf, newmask);
+ if (flags & RFTYPE_FLAGS_CPUS_LIST)
+ ret = cpulist_parse(buf, newmask);
+ else
+ ret = cpumask_parse(buf, newmask);
+
if (ret)
goto unlock;

@@ -415,7 +422,8 @@ static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
}

static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
+ char *buf, size_t nbytes, loff_t off,
+ unsigned long flags __maybe_unused)
{
struct rdtgroup *rdtgrp;
int ret = 0;
@@ -448,7 +456,8 @@ static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
}

static int rdtgroup_tasks_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
+ struct seq_file *s, void *v,
+ unsigned long flags)
{
struct rdtgroup *rdtgrp;
int ret = 0;
@@ -473,6 +482,14 @@ static struct rftype rdtgroup_base_files[] = {
.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,
.kf_ops = &rdtgroup_kf_single_ops,
@@ -489,7 +506,8 @@ static struct rftype rdtgroup_base_files[] = {
};

static int rdt_num_closids_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
+ struct seq_file *seq, void *v,
+ unsigned long flags __maybe_unused)
{
struct rdt_resource *r = of->kn->parent->priv;

@@ -499,7 +517,8 @@ static int rdt_num_closids_show(struct kernfs_open_file *of,
}

static int rdt_cbm_mask_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
+ struct seq_file *seq, void *v,
+ unsigned long flags __maybe_unused)
{
struct rdt_resource *r = of->kn->parent->priv;

@@ -509,7 +528,8 @@ static int rdt_cbm_mask_show(struct kernfs_open_file *of,
}

static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
- struct seq_file *seq, void *v)
+ struct seq_file *seq, void *v,
+ unsigned long flags __maybe_unused)
{
struct rdt_resource *r = of->kn->parent->priv;

diff --git a/arch/x86/kernel/cpu/intel_rdt_schemata.c b/arch/x86/kernel/cpu/intel_rdt_schemata.c
index f369cb8db0d5..3780ebebf36c 100644
--- a/arch/x86/kernel/cpu/intel_rdt_schemata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_schemata.c
@@ -132,7 +132,8 @@ static int update_domains(struct rdt_resource *r, int closid)
}

ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
+ char *buf, size_t nbytes, loff_t off,
+ unsigned long flags)
{
struct rdtgroup *rdtgrp;
struct rdt_resource *r;
@@ -224,7 +225,8 @@ static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
}

int rdtgroup_schemata_show(struct kernfs_open_file *of,
- struct seq_file *s, void *v)
+ struct seq_file *s, void *v,
+ unsigned long flags __maybe_unused)
{
struct rdtgroup *rdtgrp;
struct rdt_resource *r;
--
2.9.3