include/linux/cgroup-defs.h

1 /* SPDX-License-Identifier: GPL-2.0 */
3  * linux/cgroup-defs.h - basic definitions for cgroup
18 #include <linux/percpu-refcount.h>
19 #include <linux/percpu-rwsem.h>
22 #include <linux/bpf-cgroup-defs.h>
52 	CSS_ONLINE	= (1 << 1), /* between ->css_online() and ->css_offline() */
79 /* cgroup_root->flags */
130 /* cftype->flags */
149  * be obtained by setting cftype->file_offset.
159  * Per-subsystem/per-cgroup state maintained by the system.  This is the
172 	/* reference count - access via css_[try]get() and css_put() */
176 	 * siblings list anchored at the parent's ->children
183 	/* flush target list anchored at cgrp->rstat_css_list */
187 	 * PI: Subsys-unique ID.  0 is unused and root is always 1.  The
197 	 * ->children lists are in the ascending order of ->serial_nr and
221 	 * css->cgroup->nr_dying_subsys[ssid].
274 	 * On the default hierarchy, ->subsys[ssid] may point to a css
277 	 * ->subsys[ssid]->cgroup->e_csets[ssid] and provides a way to
282 	/* all threaded csets whose ->dom_cset points to this cset */
299 	 * List of csets participating in the on-going migration either as
309 	 * respectively the source and destination cgroups of the on-going
320 	/* For RCU-protected deletion */
333  * rstat - cgroup scalable recursive statistics.  Accounting is done
334  * per-cpu in cgroup_rstat_cpu which is then lazily propagated up the
346  * frequency decreases the cost of each read.
348  * This struct hosts both the fields which implement the above -
349  * updated_children and updated_next - and the fields which track basic
350  * resource statistics on top of it - bsync, bstat and last_bstat.
354 	 * ->bsync protects ->bstat.  These are the only fields which get
367 	 * This field is used to record the cumulative per-cpu time of
376 	 * deltas to propagate to the per-cpu subtree_bstat.
382 	 * are linked on the parent's ->updated_children through
383 	 * ->updated_next.
385 	 * In addition to being more compact, singly-linked list pointing
386 	 * to the cgroup makes it unnecessary for each per-cpu struct to
389 	 * Protected by per-cpu cgroup_rstat_cpu_lock.
415 	/* self css with NULL ->ss, points back to this cgroup */
447 	 * Each non-empty css_set associated with this cgroup contributes
451 	 * All children which have non-zero nr_populated_csets and/or
472 	 * ->subtree_control is the one configured through
473 	 * "cgroup.subtree_control" while ->subtree_ss_mask is the effective
475 	 * are made available iff it's enabled in ->subtree_control.
511 	 * from process granularity and no-internal-task constraint.
518 	/* per-cpu recursive resource statistics */
530 	 * A singly-linked list of cgroup structures to be rstat flushed.
591 	 * release. cgrp->ancestors[0] will be used overflowing into the
596 	/* must follow cgrp for cgrp->ancestors[0], see above */
602 	/* Hierarchy-specific flags */
608 	/* The name for this hierarchy - may be empty */
616  *	- the cgroup to use is file->f_path.dentry->d_parent->d_fsdata
617  *	- the 'cftype' of the file is file->f_path.dentry->d_fsdata
630 	 * be passed to write.  If < PAGE_SIZE-1, PAGE_SIZE-1 is assumed.
638 	 * If non-zero, should contain the offset from the start of css to
650 	struct list_head node;		/* anchored at ss->cfts */
690 	 * Maximum write size is determined by ->max_write_len.  Use
704  * See Documentation/admin-guide/cgroup-v1/cgroups.rst for details
749 	 * no-internal-process constraint are ignored and a threaded
768 	/* idr for css->id */
786 	 * is enabled on a cgroup, the depended-upon subsystems are enabled
802  * cgroup_threadgroup_change_begin - threadgroup exclusion for cgroups
814  * cgroup_threadgroup_change_end - threadgroup exclusion for cgroups
840  * sock_cgroup_data is embedded at sock->sk_cgrp_data and contains
841  * per-socket cgroup information except for memcg association.
862 	return READ_ONCE(skcd->prioidx);  in sock_cgroup_prioidx()
871 	return READ_ONCE(skcd->classid);  in sock_cgroup_classid()
881 	WRITE_ONCE(skcd->prioidx, prioidx);  in sock_cgroup_set_prioidx()
889 	WRITE_ONCE(skcd->classid, classid);  in sock_cgroup_set_classid()