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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-04-28 04:47:42 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-04-28 04:47:42 +0300 |
commit | 55e6be657b8d774d9a2e67363e5bcbbaf80fdc28 (patch) | |
tree | 30929e4dcfa6b262fcd23a91033b192a087be87d /kernel | |
parent | eb6bbacc46720b8b36eb85b2cdd91b9e691959e4 (diff) | |
parent | ffeee417d97f9171bce9f43c22c9f477e4c84f54 (diff) | |
download | linux-55e6be657b8d774d9a2e67363e5bcbbaf80fdc28.tar.xz |
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/Makefile | 1 | ||||
-rw-r--r-- | kernel/cgroup/cgroup-v1.c | 2 | ||||
-rw-r--r-- | kernel/cgroup/cpuset.c | 6 | ||||
-rw-r--r-- | kernel/cgroup/misc.c | 407 |
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, +}; |