Commit 8a693f77 authored by Tejun Heo's avatar Tejun Heo
Browse files

cgroup: Remove CFTYPE_PRESSURE 



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: default avatarTejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
parent 0083d27b

include/linux/cgroup-defs.h

+0 −1
Original line number Diff line number Diff line
@@ -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 */

kernel/cgroup/cgroup.c

+37 −27
Original line number Diff line number Diff line
@@ -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 (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,