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Commit fc5ed1e9 authored by Tejun Heo's avatar Tejun Heo
Browse files

cgroup: replace cgroup_subsys->disabled tests with cgroup_subsys_enabled() 



Replace cgroup_subsys->disabled tests in controllers with
cgroup_subsys_enabled().  cgroup_subsys_enabled() requires literal
subsys name as its parameter and thus can't be used for cgroup core
which iterates through controllers.  For cgroup core, introduce and
use cgroup_ssid_enabled() which uses slower static_key_enabled() test
and can be indexed by subsys ID.

This leaves cgroup_subsys->disabled unused.  Removed.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarZefan Li <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
parent 49d1dc4b

include/linux/cgroup-defs.h

+0 −1
Original line number Diff line number Diff line
@@ -419,7 +419,6 @@ struct cgroup_subsys { 
		     struct task_struct *task);

	void (*bind)(struct cgroup_subsys_state *root_css);



	int disabled;

	int early_init;



	/*

include/linux/hugetlb_cgroup.h

+1 −3
Original line number Diff line number Diff line
@@ -48,9 +48,7 @@ int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg) 


static inline bool hugetlb_cgroup_disabled(void)

{

	if (hugetlb_cgrp_subsys.disabled)

		return true;

	return false;

	return !cgroup_subsys_enabled(hugetlb_cgrp_subsys);

}



extern int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,

include/linux/memcontrol.h

+1 −3
Original line number Diff line number Diff line
@@ -347,9 +347,7 @@ ino_t page_cgroup_ino(struct page *page); 


static inline bool mem_cgroup_disabled(void)

{

	if (memory_cgrp_subsys.disabled)

		return true;

	return false;

	return !cgroup_subsys_enabled(memory_cgrp_subsys);

}



/*

kernel/cgroup.c

+21 −7
Original line number Diff line number Diff line
@@ -224,6 +224,19 @@ static void kill_css(struct cgroup_subsys_state *css); 
static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[],

			      bool is_add);



/**

 * cgroup_ssid_enabled - cgroup subsys enabled test by subsys ID

 * @ssid: subsys ID of interest

 *

 * cgroup_subsys_enabled() can only be used with literal subsys names which

 * is fine for individual subsystems but unsuitable for cgroup core.  This

 * is slower static_key_enabled() based test indexed by @ssid.

 */

static bool cgroup_ssid_enabled(int ssid)

{

	return static_key_enabled(cgroup_subsys_enabled_key[ssid]);

}



/* IDR wrappers which synchronize using cgroup_idr_lock */

static int cgroup_idr_alloc(struct idr *idr, void *ptr, int start, int end,

			    gfp_t gfp_mask)
@@ -1482,7 +1495,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) 
		for_each_subsys(ss, i) {

			if (strcmp(token, ss->legacy_name))

				continue;

			if (ss->disabled)

			if (!cgroup_ssid_enabled(i))

				continue;



			/* Mutually exclusive option 'all' + subsystem name */
@@ -1513,7 +1526,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) 
	 */

	if (all_ss || (!one_ss && !opts->none && !opts->name))

		for_each_subsys(ss, i)

			if (!ss->disabled)

			if (cgroup_ssid_enabled(i))

				opts->subsys_mask |= (1 << i);



	/*
@@ -2762,7 +2775,8 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of, 
		if (tok[0] == '\0')

			continue;

		for_each_subsys_which(ss, ssid, &tmp_ss_mask) {

			if (ss->disabled || strcmp(tok + 1, ss->name))

			if (!cgroup_ssid_enabled(ssid) ||

			    strcmp(tok + 1, ss->name))

				continue;



			if (*tok == '+') {
@@ -3320,7 +3334,7 @@ static int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) 
{

	int ret;



	if (ss->disabled)

	if (!cgroup_ssid_enabled(ss->id))

		return 0;



	if (!cfts || cfts[0].name[0] == '\0')
@@ -5082,7 +5096,7 @@ int __init cgroup_init(void) 
		 * disabled flag and cftype registration needs kmalloc,

		 * both of which aren't available during early_init.

		 */

		if (ss->disabled)

		if (!cgroup_ssid_enabled(ssid))

			continue;



		cgrp_dfl_root.subsys_mask |= 1 << ss->id;
@@ -5217,7 +5231,8 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v) 
	for_each_subsys(ss, i)

		seq_printf(m, "%s\t%d\t%d\t%d\n",

			   ss->legacy_name, ss->root->hierarchy_id,

			   atomic_read(&ss->root->nr_cgrps), !ss->disabled);

			   atomic_read(&ss->root->nr_cgrps),

			   cgroup_ssid_enabled(i));



	mutex_unlock(&cgroup_mutex);

	return 0;
@@ -5508,7 +5523,6 @@ static int __init cgroup_disable(char *str) 
				continue;



			static_branch_disable(cgroup_subsys_enabled_key[i]);

			ss->disabled = 1;

			printk(KERN_INFO "Disabling %s control group subsystem\n",

			       ss->name);

			break;