Merge tag 'cgroup-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:
 "Nothing too interesting:

   - Add CONFIG_DEBUG_GROUP_REF which makes cgroup refcnt operations
     kprobable

   - A couple cpuset optimizations

   - Other misc changes including doc and test updates"

* tag 'cgroup-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: remove rcu_read_lock()/rcu_read_unlock() in critical section of spin_lock_irq()
  cgroup/cpuset: Improve cpuset_css_alloc() description
  kselftest/cgroup: Add cleanup() to test_cpuset_prs.sh
  cgroup/cpuset: Optimize cpuset_attach() on v2
  cgroup/cpuset: Skip spread flags update on v2
  kselftest/cgroup: Fix gathering number of CPUs
  cgroup: cgroup refcnt functions should be exported when CONFIG_DEBUG_CGROUP_REF
  cgroup: Implement DEBUG_CGROUP_REF
This commit is contained in:
Linus Torvalds
2022-12-12 15:48:36 -08:00
6 changed files with 181 additions and 98 deletions

View File

@@ -310,71 +310,24 @@ void css_task_iter_end(struct css_task_iter *it);
* Inline functions.
*/
#ifdef CONFIG_DEBUG_CGROUP_REF
void css_get(struct cgroup_subsys_state *css);
void css_get_many(struct cgroup_subsys_state *css, unsigned int n);
bool css_tryget(struct cgroup_subsys_state *css);
bool css_tryget_online(struct cgroup_subsys_state *css);
void css_put(struct cgroup_subsys_state *css);
void css_put_many(struct cgroup_subsys_state *css, unsigned int n);
#else
#define CGROUP_REF_FN_ATTRS static inline
#define CGROUP_REF_EXPORT(fn)
#include <linux/cgroup_refcnt.h>
#endif
static inline u64 cgroup_id(const struct cgroup *cgrp)
{
return cgrp->kn->id;
}
/**
* css_get - obtain a reference on the specified css
* @css: target css
*
* The caller must already have a reference.
*/
static inline void css_get(struct cgroup_subsys_state *css)
{
if (!(css->flags & CSS_NO_REF))
percpu_ref_get(&css->refcnt);
}
/**
* css_get_many - obtain references on the specified css
* @css: target css
* @n: number of references to get
*
* The caller must already have a reference.
*/
static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n)
{
if (!(css->flags & CSS_NO_REF))
percpu_ref_get_many(&css->refcnt, n);
}
/**
* css_tryget - try to obtain a reference on the specified css
* @css: target css
*
* Obtain a reference on @css unless it already has reached zero and is
* being released. This function doesn't care whether @css is on or
* offline. The caller naturally needs to ensure that @css is accessible
* but doesn't have to be holding a reference on it - IOW, RCU protected
* access is good enough for this function. Returns %true if a reference
* count was successfully obtained; %false otherwise.
*/
static inline bool css_tryget(struct cgroup_subsys_state *css)
{
if (!(css->flags & CSS_NO_REF))
return percpu_ref_tryget(&css->refcnt);
return true;
}
/**
* css_tryget_online - try to obtain a reference on the specified css if online
* @css: target css
*
* Obtain a reference on @css if it's online. The caller naturally needs
* to ensure that @css is accessible but doesn't have to be holding a
* reference on it - IOW, RCU protected access is good enough for this
* function. Returns %true if a reference count was successfully obtained;
* %false otherwise.
*/
static inline bool css_tryget_online(struct cgroup_subsys_state *css)
{
if (!(css->flags & CSS_NO_REF))
return percpu_ref_tryget_live(&css->refcnt);
return true;
}
/**
* css_is_dying - test whether the specified css is dying
* @css: target css
@@ -395,31 +348,6 @@ static inline bool css_is_dying(struct cgroup_subsys_state *css)
return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(&css->refcnt);
}
/**
* css_put - put a css reference
* @css: target css
*
* Put a reference obtained via css_get() and css_tryget_online().
*/
static inline void css_put(struct cgroup_subsys_state *css)
{
if (!(css->flags & CSS_NO_REF))
percpu_ref_put(&css->refcnt);
}
/**
* css_put_many - put css references
* @css: target css
* @n: number of references to put
*
* Put references obtained via css_get() and css_tryget_online().
*/
static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
{
if (!(css->flags & CSS_NO_REF))
percpu_ref_put_many(&css->refcnt, n);
}
static inline void cgroup_get(struct cgroup *cgrp)
{
css_get(&cgrp->self);