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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-27 18:47:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-27 18:47:42 -0700
commit55e6be657b8d774d9a2e67363e5bcbbaf80fdc28 (patch)
tree30929e4dcfa6b262fcd23a91033b192a087be87d /kernel
parenteb6bbacc46720b8b36eb85b2cdd91b9e691959e4 (diff)
parentffeee417d97f9171bce9f43c22c9f477e4c84f54 (diff)
Merge branch 'for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup changes from Tejun Heo: "The only notable change is Vipin's new misc cgroup controller. This implements generic support for resources which can be controlled by simply counting and limiting the number of resource instances - ie there's X number of these on the system and this cgroup subtree can have upto Y of those. The first user is the address space IDs used for virtual machine memory encryption and expected future usages are similar - niche hardware features with concrete resource limits and simple usage models" * 'for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: use tsk->in_iowait instead of delayacct_is_task_waiting_on_io() cgroup/cpuset: fix typos in comments cgroup: misc: mark dummy misc_cg_res_total_usage() static inline svm/sev: Register SEV and SEV-ES ASIDs to the misc controller cgroup: Miscellaneous cgroup documentation. cgroup: Add misc cgroup controller
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup/Makefile1
-rw-r--r--kernel/cgroup/cgroup-v1.c2
-rw-r--r--kernel/cgroup/cpuset.c6
-rw-r--r--kernel/cgroup/misc.c407
4 files changed, 412 insertions, 4 deletions
diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile
index 5d7a76bfbbb7..12f8457ad1f9 100644
--- a/kernel/cgroup/Makefile
+++ b/kernel/cgroup/Makefile
@@ -5,4 +5,5 @@ obj-$(CONFIG_CGROUP_FREEZER) += legacy_freezer.o
obj-$(CONFIG_CGROUP_PIDS) += pids.o
obj-$(CONFIG_CGROUP_RDMA) += rdma.o
obj-$(CONFIG_CPUSETS) += cpuset.o
+obj-$(CONFIG_CGROUP_MISC) += misc.o
obj-$(CONFIG_CGROUP_DEBUG) += debug.o
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index a5751784ad74..391aa570369b 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -727,7 +727,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
stats->nr_stopped++;
break;
default:
- if (delayacct_is_task_waiting_on_io(tsk))
+ if (tsk->in_iowait)
stats->nr_io_wait++;
break;
}
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 5258b68153e0..a945504c0ae7 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -585,7 +585,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
par = parent_cs(cur);
- /* On legacy hiearchy, we must be a subset of our parent cpuset. */
+ /* On legacy hierarchy, we must be a subset of our parent cpuset. */
ret = -EACCES;
if (!is_in_v2_mode() && !is_cpuset_subset(trial, par))
goto out;
@@ -1726,7 +1726,7 @@ static void update_tasks_nodemask(struct cpuset *cs)
* When configured nodemask is changed, the effective nodemasks of this cpuset
* and all its descendants need to be updated.
*
- * On legacy hiearchy, effective_mems will be the same with mems_allowed.
+ * On legacy hierarchy, effective_mems will be the same with mems_allowed.
*
* Called with cpuset_mutex held
*/
@@ -2500,7 +2500,7 @@ static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
BUG();
}
- /* Unrechable but makes gcc happy */
+ /* Unreachable but makes gcc happy */
return 0;
}
diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c
new file mode 100644
index 000000000000..ec02d963cad1
--- /dev/null
+++ b/kernel/cgroup/misc.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Miscellaneous cgroup controller
+ *
+ * Copyright 2020 Google LLC
+ * Author: Vipin Sharma <vipinsh@google.com>
+ */
+
+#include <linux/limits.h>
+#include <linux/cgroup.h>
+#include <linux/errno.h>
+#include <linux/atomic.h>
+#include <linux/slab.h>
+#include <linux/misc_cgroup.h>
+
+#define MAX_STR "max"
+#define MAX_NUM ULONG_MAX
+
+/* Miscellaneous res name, keep it in sync with enum misc_res_type */
+static const char *const misc_res_name[] = {
+#ifdef CONFIG_KVM_AMD_SEV
+ /* AMD SEV ASIDs resource */
+ "sev",
+ /* AMD SEV-ES ASIDs resource */
+ "sev_es",
+#endif
+};
+
+/* Root misc cgroup */
+static struct misc_cg root_cg;
+
+/*
+ * Miscellaneous resources capacity for the entire machine. 0 capacity means
+ * resource is not initialized or not present in the host.
+ *
+ * root_cg.max and capacity are independent of each other. root_cg.max can be
+ * more than the actual capacity. We are using Limits resource distribution
+ * model of cgroup for miscellaneous controller.
+ */
+static unsigned long misc_res_capacity[MISC_CG_RES_TYPES];
+
+/**
+ * parent_misc() - Get the parent of the passed misc cgroup.
+ * @cgroup: cgroup whose parent needs to be fetched.
+ *
+ * Context: Any context.
+ * Return:
+ * * struct misc_cg* - Parent of the @cgroup.
+ * * %NULL - If @cgroup is null or the passed cgroup does not have a parent.
+ */
+static struct misc_cg *parent_misc(struct misc_cg *cgroup)
+{
+ return cgroup ? css_misc(cgroup->css.parent) : NULL;
+}
+
+/**
+ * valid_type() - Check if @type is valid or not.
+ * @type: misc res type.
+ *
+ * Context: Any context.
+ * Return:
+ * * true - If valid type.
+ * * false - If not valid type.
+ */
+static inline bool valid_type(enum misc_res_type type)
+{
+ return type >= 0 && type < MISC_CG_RES_TYPES;
+}
+
+/**
+ * misc_cg_res_total_usage() - Get the current total usage of the resource.
+ * @type: misc res type.
+ *
+ * Context: Any context.
+ * Return: Current total usage of the resource.
+ */
+unsigned long misc_cg_res_total_usage(enum misc_res_type type)
+{
+ if (valid_type(type))
+ return atomic_long_read(&root_cg.res[type].usage);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(misc_cg_res_total_usage);
+
+/**
+ * misc_cg_set_capacity() - Set the capacity of the misc cgroup res.
+ * @type: Type of the misc res.
+ * @capacity: Supported capacity of the misc res on the host.
+ *
+ * If capacity is 0 then the charging a misc cgroup fails for that type.
+ *
+ * Context: Any context.
+ * Return:
+ * * %0 - Successfully registered the capacity.
+ * * %-EINVAL - If @type is invalid.
+ */
+int misc_cg_set_capacity(enum misc_res_type type, unsigned long capacity)
+{
+ if (!valid_type(type))
+ return -EINVAL;
+
+ WRITE_ONCE(misc_res_capacity[type], capacity);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(misc_cg_set_capacity);
+
+/**
+ * misc_cg_cancel_charge() - Cancel the charge from the misc cgroup.
+ * @type: Misc res type in misc cg to cancel the charge from.
+ * @cg: Misc cgroup to cancel charge from.
+ * @amount: Amount to cancel.
+ *
+ * Context: Any context.
+ */
+static void misc_cg_cancel_charge(enum misc_res_type type, struct misc_cg *cg,
+ unsigned long amount)
+{
+ WARN_ONCE(atomic_long_add_negative(-amount, &cg->res[type].usage),
+ "misc cgroup resource %s became less than 0",
+ misc_res_name[type]);
+}
+
+/**
+ * misc_cg_try_charge() - Try charging the misc cgroup.
+ * @type: Misc res type to charge.
+ * @cg: Misc cgroup which will be charged.
+ * @amount: Amount to charge.
+ *
+ * Charge @amount to the misc cgroup. Caller must use the same cgroup during
+ * the uncharge call.
+ *
+ * Context: Any context.
+ * Return:
+ * * %0 - If successfully charged.
+ * * -EINVAL - If @type is invalid or misc res has 0 capacity.
+ * * -EBUSY - If max limit will be crossed or total usage will be more than the
+ * capacity.
+ */
+int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg,
+ unsigned long amount)
+{
+ struct misc_cg *i, *j;
+ int ret;
+ struct misc_res *res;
+ int new_usage;
+
+ if (!(valid_type(type) && cg && READ_ONCE(misc_res_capacity[type])))
+ return -EINVAL;
+
+ if (!amount)
+ return 0;
+
+ for (i = cg; i; i = parent_misc(i)) {
+ res = &i->res[type];
+
+ new_usage = atomic_long_add_return(amount, &res->usage);
+ if (new_usage > READ_ONCE(res->max) ||
+ new_usage > READ_ONCE(misc_res_capacity[type])) {
+ if (!res->failed) {
+ pr_info("cgroup: charge rejected by the misc controller for %s resource in ",
+ misc_res_name[type]);
+ pr_cont_cgroup_path(i->css.cgroup);
+ pr_cont("\n");
+ res->failed = true;
+ }
+ ret = -EBUSY;
+ goto err_charge;
+ }
+ }
+ return 0;
+
+err_charge:
+ for (j = cg; j != i; j = parent_misc(j))
+ misc_cg_cancel_charge(type, j, amount);
+ misc_cg_cancel_charge(type, i, amount);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(misc_cg_try_charge);
+
+/**
+ * misc_cg_uncharge() - Uncharge the misc cgroup.
+ * @type: Misc res type which was charged.
+ * @cg: Misc cgroup which will be uncharged.
+ * @amount: Charged amount.
+ *
+ * Context: Any context.
+ */
+void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg,
+ unsigned long amount)
+{
+ struct misc_cg *i;
+
+ if (!(amount && valid_type(type) && cg))
+ return;
+
+ for (i = cg; i; i = parent_misc(i))
+ misc_cg_cancel_charge(type, i, amount);
+}
+EXPORT_SYMBOL_GPL(misc_cg_uncharge);
+
+/**
+ * misc_cg_max_show() - Show the misc cgroup max limit.
+ * @sf: Interface file
+ * @v: Arguments passed
+ *
+ * Context: Any context.
+ * Return: 0 to denote successful print.
+ */
+static int misc_cg_max_show(struct seq_file *sf, void *v)
+{
+ int i;
+ struct misc_cg *cg = css_misc(seq_css(sf));
+ unsigned long max;
+
+ for (i = 0; i < MISC_CG_RES_TYPES; i++) {
+ if (READ_ONCE(misc_res_capacity[i])) {
+ max = READ_ONCE(cg->res[i].max);
+ if (max == MAX_NUM)
+ seq_printf(sf, "%s max\n", misc_res_name[i]);
+ else
+ seq_printf(sf, "%s %lu\n", misc_res_name[i],
+ max);
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * misc_cg_max_write() - Update the maximum limit of the cgroup.
+ * @of: Handler for the file.
+ * @buf: Data from the user. It should be either "max", 0, or a positive
+ * integer.
+ * @nbytes: Number of bytes of the data.
+ * @off: Offset in the file.
+ *
+ * User can pass data like:
+ * echo sev 23 > misc.max, OR
+ * echo sev max > misc.max
+ *
+ * Context: Any context.
+ * Return:
+ * * >= 0 - Number of bytes processed in the input.
+ * * -EINVAL - If buf is not valid.
+ * * -ERANGE - If number is bigger than the unsigned long capacity.
+ */
+static ssize_t misc_cg_max_write(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off)
+{
+ struct misc_cg *cg;
+ unsigned long max;
+ int ret = 0, i;
+ enum misc_res_type type = MISC_CG_RES_TYPES;
+ char *token;
+
+ buf = strstrip(buf);
+ token = strsep(&buf, " ");
+
+ if (!token || !buf)
+ return -EINVAL;
+
+ for (i = 0; i < MISC_CG_RES_TYPES; i++) {
+ if (!strcmp(misc_res_name[i], token)) {
+ type = i;
+ break;
+ }
+ }
+
+ if (type == MISC_CG_RES_TYPES)
+ return -EINVAL;
+
+ if (!strcmp(MAX_STR, buf)) {
+ max = MAX_NUM;
+ } else {
+ ret = kstrtoul(buf, 0, &max);
+ if (ret)
+ return ret;
+ }
+
+ cg = css_misc(of_css(of));
+
+ if (READ_ONCE(misc_res_capacity[type]))
+ WRITE_ONCE(cg->res[type].max, max);
+ else
+ ret = -EINVAL;
+
+ return ret ? ret : nbytes;
+}
+
+/**
+ * misc_cg_current_show() - Show the current usage of the misc cgroup.
+ * @sf: Interface file
+ * @v: Arguments passed
+ *
+ * Context: Any context.
+ * Return: 0 to denote successful print.
+ */
+static int misc_cg_current_show(struct seq_file *sf, void *v)
+{
+ int i;
+ unsigned long usage;
+ struct misc_cg *cg = css_misc(seq_css(sf));
+
+ for (i = 0; i < MISC_CG_RES_TYPES; i++) {
+ usage = atomic_long_read(&cg->res[i].usage);
+ if (READ_ONCE(misc_res_capacity[i]) || usage)
+ seq_printf(sf, "%s %lu\n", misc_res_name[i], usage);
+ }
+
+ return 0;
+}
+
+/**
+ * misc_cg_capacity_show() - Show the total capacity of misc res on the host.
+ * @sf: Interface file
+ * @v: Arguments passed
+ *
+ * Only present in the root cgroup directory.
+ *
+ * Context: Any context.
+ * Return: 0 to denote successful print.
+ */
+static int misc_cg_capacity_show(struct seq_file *sf, void *v)
+{
+ int i;
+ unsigned long cap;
+
+ for (i = 0; i < MISC_CG_RES_TYPES; i++) {
+ cap = READ_ONCE(misc_res_capacity[i]);
+ if (cap)
+ seq_printf(sf, "%s %lu\n", misc_res_name[i], cap);
+ }
+
+ return 0;
+}
+
+/* Misc cgroup interface files */
+static struct cftype misc_cg_files[] = {
+ {
+ .name = "max",
+ .write = misc_cg_max_write,
+ .seq_show = misc_cg_max_show,
+ .flags = CFTYPE_NOT_ON_ROOT,
+ },
+ {
+ .name = "current",
+ .seq_show = misc_cg_current_show,
+ .flags = CFTYPE_NOT_ON_ROOT,
+ },
+ {
+ .name = "capacity",
+ .seq_show = misc_cg_capacity_show,
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ },
+ {}
+};
+
+/**
+ * misc_cg_alloc() - Allocate misc cgroup.
+ * @parent_css: Parent cgroup.
+ *
+ * Context: Process context.
+ * Return:
+ * * struct cgroup_subsys_state* - css of the allocated cgroup.
+ * * ERR_PTR(-ENOMEM) - No memory available to allocate.
+ */
+static struct cgroup_subsys_state *
+misc_cg_alloc(struct cgroup_subsys_state *parent_css)
+{
+ enum misc_res_type i;
+ struct misc_cg *cg;
+
+ if (!parent_css) {
+ cg = &root_cg;
+ } else {
+ cg = kzalloc(sizeof(*cg), GFP_KERNEL);
+ if (!cg)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ for (i = 0; i < MISC_CG_RES_TYPES; i++) {
+ WRITE_ONCE(cg->res[i].max, MAX_NUM);
+ atomic_long_set(&cg->res[i].usage, 0);
+ }
+
+ return &cg->css;
+}
+
+/**
+ * misc_cg_free() - Free the misc cgroup.
+ * @css: cgroup subsys object.
+ *
+ * Context: Any context.
+ */
+static void misc_cg_free(struct cgroup_subsys_state *css)
+{
+ kfree(css_misc(css));
+}
+
+/* Cgroup controller callbacks */
+struct cgroup_subsys misc_cgrp_subsys = {
+ .css_alloc = misc_cg_alloc,
+ .css_free = misc_cg_free,
+ .legacy_cftypes = misc_cg_files,
+ .dfl_cftypes = misc_cg_files,
+};