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cgroup: Remove CFTYPE_PRESSURE

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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@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
This commit is contained in:
Tejun Heo 2022-09-06 09:38:55 -10:00
parent 0083d27b21
commit 8a693f7766
2 changed files with 36 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/cgroup-defs.h
View File

@ -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 */

62
kernel/cgroup/cgroup.c
View File

@ -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_subsys_state *css)
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 cgroup_subsys_state *css)
return 0;
if (!css->ss) {
if (cgroup_on_dfl(cgrp))
cfts = cgroup_base_files;
else
cfts = cgroup1_base_files;
if (cgroup_on_dfl(cgrp)) {
ret = cgroup_addrm_files(&cgrp->self, cgrp,
cgroup_base_files, true);
if (ret < 0)
return ret;
ret = cgroup_addrm_files(&cgrp->self, cgrp, cfts, 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);
@ -4132,8 +4145,6 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css,
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))
@ -4218,9 +4229,6 @@ static int cgroup_init_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
break;
}
if ((cft->flags & CFTYPE_PRESSURE) && !cgroup_psi_enabled())
continue;
if (cft->seq_start)
kf_ops = &cgroup_kf_ops;
else
@ -5144,10 +5152,13 @@ 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,
@ -5155,7 +5166,6 @@ 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,
@ -5163,7 +5173,6 @@ 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,
@ -5930,6 +5939,7 @@ 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();
@ -6821,9 +6831,6 @@ static ssize_t show_delegatable_files(struct cftype *files, char *buf,
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);
@ -6843,8 +6850,11 @@ static ssize_t delegate_show(struct kobject *kobj, struct kobj_attribute *attr,
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,