CFTYPE_PRESSURE is used to flag PSI related files so that they are not
created if PSI is disabled during boot. It's a bit weird to use a generic
flag to mark a specific file type. Let's instead move the PSI files into its
own cftypes array and add/rm them conditionally. This is a bit more code but
cleaner.
No userland visible changes.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
---
include/linux/cgroup-defs.h | 1
kernel/cgroup/cgroup.c | 64 +++++++++++++++++++++++++-------------------
2 files changed, 37 insertions(+), 28 deletions(-)
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -126,7 +126,6 @@ enum {
CFTYPE_NO_PREFIX = (1 << 3), /* (DON'T USE FOR NEW FILES) no subsys prefix */
CFTYPE_WORLD_WRITABLE = (1 << 4), /* (DON'T USE FOR NEW FILES) S_IWUGO */
CFTYPE_DEBUG = (1 << 5), /* create when cgroup_debug */
- CFTYPE_PRESSURE = (1 << 6), /* only if pressure feature is enabled */
/* internal flags, do not use outside cgroup core proper */
__CFTYPE_ONLY_ON_DFL = (1 << 16), /* only on default hierarchy */
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -217,6 +217,7 @@ struct cgroup_namespace init_cgroup_ns =
static struct file_system_type cgroup2_fs_type;
static struct cftype cgroup_base_files[];
+static struct cftype cgroup_psi_files[];
/* cgroup optional features */
enum cgroup_opt_features {
@@ -1689,12 +1690,16 @@ static void css_clear_dir(struct cgroup_
css->flags &= ~CSS_VISIBLE;
if (!css->ss) {
- if (cgroup_on_dfl(cgrp))
- cfts = cgroup_base_files;
- else
- cfts = cgroup1_base_files;
-
- cgroup_addrm_files(css, cgrp, cfts, false);
+ if (cgroup_on_dfl(cgrp)) {
+ cgroup_addrm_files(css, cgrp,
+ cgroup_base_files, false);
+ if (cgroup_psi_enabled())
+ cgroup_addrm_files(css, cgrp,
+ cgroup_psi_files, false);
+ } else {
+ cgroup_addrm_files(css, cgrp,
+ cgroup1_base_files, false);
+ }
} else {
list_for_each_entry(cfts, &css->ss->cfts, node)
cgroup_addrm_files(css, cgrp, cfts, false);
@@ -1717,14 +1722,22 @@ static int css_populate_dir(struct cgrou
return 0;
if (!css->ss) {
- if (cgroup_on_dfl(cgrp))
- cfts = cgroup_base_files;
- else
- cfts = cgroup1_base_files;
-
- ret = cgroup_addrm_files(&cgrp->self, cgrp, cfts, true);
- if (ret < 0)
- return ret;
+ if (cgroup_on_dfl(cgrp)) {
+ ret = cgroup_addrm_files(&cgrp->self, cgrp,
+ cgroup_base_files, true);
+ if (ret < 0)
+ return ret;
+
+ if (cgroup_psi_enabled()) {
+ ret = cgroup_addrm_files(&cgrp->self, cgrp,
+ cgroup_psi_files, true);
+ if (ret < 0)
+ return ret;
+ }
+ } else {
+ cgroup_addrm_files(css, cgrp,
+ cgroup1_base_files, true);
+ }
} else {
list_for_each_entry(cfts, &css->ss->cfts, node) {
ret = cgroup_addrm_files(css, cgrp, cfts, true);
@@ -4100,8 +4113,6 @@ static int cgroup_addrm_files(struct cgr
restart:
for (cft = cfts; cft != cft_end && cft->name[0] != '\0'; cft++) {
/* does cft->flags tell us to skip this file on @cgrp? */
- if ((cft->flags & CFTYPE_PRESSURE) && !cgroup_psi_enabled())
- continue;
if ((cft->flags & __CFTYPE_ONLY_ON_DFL) && !cgroup_on_dfl(cgrp))
continue;
if ((cft->flags & __CFTYPE_NOT_ON_DFL) && cgroup_on_dfl(cgrp))
@@ -4186,9 +4197,6 @@ static int cgroup_init_cftypes(struct cg
break;
}
- if ((cft->flags & CFTYPE_PRESSURE) && !cgroup_psi_enabled())
- continue;
-
if (cft->seq_start)
kf_ops = &cgroup_kf_ops;
else
@@ -5134,10 +5142,13 @@ static struct cftype cgroup_base_files[]
.name = "cpu.stat",
.seq_show = cpu_stat_show,
},
+ { } /* terminate */
+};
+
+static struct cftype cgroup_psi_files[] = {
#ifdef CONFIG_PSI
{
.name = "io.pressure",
- .flags = CFTYPE_PRESSURE,
.seq_show = cgroup_io_pressure_show,
.write = cgroup_io_pressure_write,
.poll = cgroup_pressure_poll,
@@ -5145,7 +5156,6 @@ static struct cftype cgroup_base_files[]
},
{
.name = "memory.pressure",
- .flags = CFTYPE_PRESSURE,
.seq_show = cgroup_memory_pressure_show,
.write = cgroup_memory_pressure_write,
.poll = cgroup_pressure_poll,
@@ -5153,7 +5163,6 @@ static struct cftype cgroup_base_files[]
},
{
.name = "cpu.pressure",
- .flags = CFTYPE_PRESSURE,
.seq_show = cgroup_cpu_pressure_show,
.write = cgroup_cpu_pressure_write,
.poll = cgroup_pressure_poll,
@@ -5921,6 +5930,7 @@ int __init cgroup_init(void)
BUILD_BUG_ON(CGROUP_SUBSYS_COUNT > 16);
BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files));
+ BUG_ON(cgroup_init_cftypes(NULL, cgroup_psi_files));
BUG_ON(cgroup_init_cftypes(NULL, cgroup1_base_files));
cgroup_rstat_boot();
@@ -6792,9 +6802,6 @@ static ssize_t show_delegatable_files(st
if (!(cft->flags & CFTYPE_NS_DELEGATABLE))
continue;
- if ((cft->flags & CFTYPE_PRESSURE) && !cgroup_psi_enabled())
- continue;
-
if (prefix)
ret += snprintf(buf + ret, size - ret, "%s.", prefix);
@@ -6814,8 +6821,11 @@ static ssize_t delegate_show(struct kobj
int ssid;
ssize_t ret = 0;
- ret = show_delegatable_files(cgroup_base_files, buf, PAGE_SIZE - ret,
- NULL);
+ ret = show_delegatable_files(cgroup_base_files, buf + ret,
+ PAGE_SIZE - ret, NULL);
+ if (cgroup_psi_enabled())
+ ret += show_delegatable_files(cgroup_psi_files, buf + ret,
+ PAGE_SIZE - ret, NULL);
for_each_subsys(ss, ssid)
ret += show_delegatable_files(ss->dfl_cftypes, buf + ret,
