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cpuset: replace cgroup_mutex locking with cpuset internal locking
Supposedly for historical reasons, cpuset depends on cgroup core for locking. It depends on cgroup_mutex in cgroup callbacks and grabs cgroup_mutex from other places where it wants to be synchronized. This is majorly messy and highly prone to introducing circular locking dependency especially because cgroup_mutex is supposed to be one of the outermost locks. As previous patches already plugged possible races which may happen by decoupling from cgroup_mutex, replacing cgroup_mutex with cpuset specific cpuset_mutex is mostly straight-forward. Introduce cpuset_mutex, replace all occurrences of cgroup_mutex with it, and add cpuset_mutex locking to places which inherited cgroup_mutex from cgroup core. The only complication is from cpuset wanting to initiate task migration when a cpuset loses all cpus or memory nodes. Task migration may go through full cgroup and all subsystem locking and should be initiated without holding any cpuset specific lock; however, a previous patch already made hotplug handled asynchronously and moving the task migration part outside other locks is easy. cpuset_propagate_hotplug_workfn() now invokes remove_tasks_in_empty_cpuset() without holding any lock. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
This commit is contained in:
Tejun Heo
parent
02bb586372
commit
5d21cc2db0
186
kernel/cpuset.c
186
kernel/cpuset.c
@ -208,23 +208,20 @@ static struct cpuset top_cpuset = {
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if (is_cpuset_online(((child_cs) = cgroup_cs((pos_cgrp)))))
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/*
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* There are two global mutexes guarding cpuset structures. The first
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* is the main control groups cgroup_mutex, accessed via
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* cgroup_lock()/cgroup_unlock(). The second is the cpuset-specific
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* callback_mutex, below. They can nest. It is ok to first take
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* cgroup_mutex, then nest callback_mutex. We also require taking
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* task_lock() when dereferencing a task's cpuset pointer. See "The
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* task_lock() exception", at the end of this comment.
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* There are two global mutexes guarding cpuset structures - cpuset_mutex
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* and callback_mutex. The latter may nest inside the former. We also
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* require taking task_lock() when dereferencing a task's cpuset pointer.
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* See "The task_lock() exception", at the end of this comment.
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*
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* A task must hold both mutexes to modify cpusets. If a task
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* holds cgroup_mutex, then it blocks others wanting that mutex,
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* ensuring that it is the only task able to also acquire callback_mutex
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* and be able to modify cpusets. It can perform various checks on
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* the cpuset structure first, knowing nothing will change. It can
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* also allocate memory while just holding cgroup_mutex. While it is
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* performing these checks, various callback routines can briefly
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* acquire callback_mutex to query cpusets. Once it is ready to make
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* the changes, it takes callback_mutex, blocking everyone else.
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* A task must hold both mutexes to modify cpusets. If a task holds
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* cpuset_mutex, then it blocks others wanting that mutex, ensuring that it
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* is the only task able to also acquire callback_mutex and be able to
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* modify cpusets. It can perform various checks on the cpuset structure
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* first, knowing nothing will change. It can also allocate memory while
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* just holding cpuset_mutex. While it is performing these checks, various
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* callback routines can briefly acquire callback_mutex to query cpusets.
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* Once it is ready to make the changes, it takes callback_mutex, blocking
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* everyone else.
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*
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* Calls to the kernel memory allocator can not be made while holding
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* callback_mutex, as that would risk double tripping on callback_mutex
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@ -246,6 +243,7 @@ static struct cpuset top_cpuset = {
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* guidelines for accessing subsystem state in kernel/cgroup.c
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*/
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static DEFINE_MUTEX(cpuset_mutex);
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static DEFINE_MUTEX(callback_mutex);
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/*
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@ -351,7 +349,7 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
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/*
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* update task's spread flag if cpuset's page/slab spread flag is set
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*
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* Called with callback_mutex/cgroup_mutex held
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* Called with callback_mutex/cpuset_mutex held
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*/
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static void cpuset_update_task_spread_flag(struct cpuset *cs,
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struct task_struct *tsk)
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@ -371,7 +369,7 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs,
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*
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* One cpuset is a subset of another if all its allowed CPUs and
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* Memory Nodes are a subset of the other, and its exclusive flags
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* are only set if the other's are set. Call holding cgroup_mutex.
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* are only set if the other's are set. Call holding cpuset_mutex.
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*/
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static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
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@ -420,7 +418,7 @@ static void free_trial_cpuset(struct cpuset *trial)
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* If we replaced the flag and mask values of the current cpuset
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* (cur) with those values in the trial cpuset (trial), would
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* our various subset and exclusive rules still be valid? Presumes
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* cgroup_mutex held.
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* cpuset_mutex held.
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*
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* 'cur' is the address of an actual, in-use cpuset. Operations
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* such as list traversal that depend on the actual address of the
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@ -555,7 +553,7 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
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* domains when operating in the severe memory shortage situations
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* that could cause allocation failures below.
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*
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* Must be called with cgroup_lock held.
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* Must be called with cpuset_mutex held.
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*
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* The three key local variables below are:
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* q - a linked-list queue of cpuset pointers, used to implement a
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@ -766,7 +764,7 @@ done:
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* 'cpus' is removed, then call this routine to rebuild the
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* scheduler's dynamic sched domains.
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*
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* Call with cgroup_mutex held. Takes get_online_cpus().
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* Call with cpuset_mutex held. Takes get_online_cpus().
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*/
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static void rebuild_sched_domains_locked(void)
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{
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@ -774,7 +772,7 @@ static void rebuild_sched_domains_locked(void)
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cpumask_var_t *doms;
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int ndoms;
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WARN_ON_ONCE(!cgroup_lock_is_held());
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lockdep_assert_held(&cpuset_mutex);
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get_online_cpus();
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/* Generate domain masks and attrs */
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@ -800,9 +798,9 @@ static int generate_sched_domains(cpumask_var_t **domains,
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void rebuild_sched_domains(void)
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{
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cgroup_lock();
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mutex_lock(&cpuset_mutex);
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rebuild_sched_domains_locked();
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cgroup_unlock();
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mutex_unlock(&cpuset_mutex);
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}
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/**
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@ -810,7 +808,7 @@ void rebuild_sched_domains(void)
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* @tsk: task to test
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* @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner
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*
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* Call with cgroup_mutex held. May take callback_mutex during call.
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* Call with cpuset_mutex held. May take callback_mutex during call.
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* Called for each task in a cgroup by cgroup_scan_tasks().
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* Return nonzero if this tasks's cpus_allowed mask should be changed (in other
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* words, if its mask is not equal to its cpuset's mask).
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@ -831,7 +829,7 @@ static int cpuset_test_cpumask(struct task_struct *tsk,
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* cpus_allowed mask needs to be changed.
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*
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* We don't need to re-check for the cgroup/cpuset membership, since we're
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* holding cgroup_lock() at this point.
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* holding cpuset_mutex at this point.
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*/
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static void cpuset_change_cpumask(struct task_struct *tsk,
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struct cgroup_scanner *scan)
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@ -844,7 +842,7 @@ static void cpuset_change_cpumask(struct task_struct *tsk,
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* @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
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* @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
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*
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* Called with cgroup_mutex held
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* Called with cpuset_mutex held
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*
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* The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
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* calling callback functions for each.
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@ -934,7 +932,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
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* Temporarilly set tasks mems_allowed to target nodes of migration,
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* so that the migration code can allocate pages on these nodes.
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*
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* Call holding cgroup_mutex, so current's cpuset won't change
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* Call holding cpuset_mutex, so current's cpuset won't change
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* during this call, as manage_mutex holds off any cpuset_attach()
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* calls. Therefore we don't need to take task_lock around the
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* call to guarantee_online_mems(), as we know no one is changing
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@ -1009,7 +1007,7 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk,
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/*
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* Update task's mems_allowed and rebind its mempolicy and vmas' mempolicy
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* of it to cpuset's new mems_allowed, and migrate pages to new nodes if
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* memory_migrate flag is set. Called with cgroup_mutex held.
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* memory_migrate flag is set. Called with cpuset_mutex held.
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*/
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static void cpuset_change_nodemask(struct task_struct *p,
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struct cgroup_scanner *scan)
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@ -1018,7 +1016,7 @@ static void cpuset_change_nodemask(struct task_struct *p,
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struct cpuset *cs;
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int migrate;
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const nodemask_t *oldmem = scan->data;
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static nodemask_t newmems; /* protected by cgroup_mutex */
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static nodemask_t newmems; /* protected by cpuset_mutex */
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cs = cgroup_cs(scan->cg);
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guarantee_online_mems(cs, &newmems);
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@ -1045,7 +1043,7 @@ static void *cpuset_being_rebound;
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* @oldmem: old mems_allowed of cpuset cs
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* @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
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*
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* Called with cgroup_mutex held
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* Called with cpuset_mutex held
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* No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
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* if @heap != NULL.
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*/
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@ -1067,7 +1065,7 @@ static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem,
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* take while holding tasklist_lock. Forks can happen - the
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* mpol_dup() cpuset_being_rebound check will catch such forks,
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* and rebind their vma mempolicies too. Because we still hold
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* the global cgroup_mutex, we know that no other rebind effort
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* the global cpuset_mutex, we know that no other rebind effort
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* will be contending for the global variable cpuset_being_rebound.
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* It's ok if we rebind the same mm twice; mpol_rebind_mm()
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* is idempotent. Also migrate pages in each mm to new nodes.
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@ -1086,7 +1084,7 @@ static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem,
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* mempolicies and if the cpuset is marked 'memory_migrate',
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* migrate the tasks pages to the new memory.
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*
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* Call with cgroup_mutex held. May take callback_mutex during call.
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* Call with cpuset_mutex held. May take callback_mutex during call.
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* Will take tasklist_lock, scan tasklist for tasks in cpuset cs,
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* lock each such tasks mm->mmap_sem, scan its vma's and rebind
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* their mempolicies to the cpusets new mems_allowed.
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@ -1184,7 +1182,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val)
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* Called by cgroup_scan_tasks() for each task in a cgroup.
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*
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* We don't need to re-check for the cgroup/cpuset membership, since we're
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* holding cgroup_lock() at this point.
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* holding cpuset_mutex at this point.
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*/
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static void cpuset_change_flag(struct task_struct *tsk,
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struct cgroup_scanner *scan)
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@ -1197,7 +1195,7 @@ static void cpuset_change_flag(struct task_struct *tsk,
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* @cs: the cpuset in which each task's spread flags needs to be changed
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* @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
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*
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* Called with cgroup_mutex held
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* Called with cpuset_mutex held
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*
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* The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
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* calling callback functions for each.
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@ -1222,7 +1220,7 @@ static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap)
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* cs: the cpuset to update
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* turning_on: whether the flag is being set or cleared
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*
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* Call with cgroup_mutex held.
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* Call with cpuset_mutex held.
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*/
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static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
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@ -1370,15 +1368,18 @@ static int fmeter_getrate(struct fmeter *fmp)
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return val;
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}
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/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
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/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
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static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
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{
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struct cpuset *cs = cgroup_cs(cgrp);
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struct task_struct *task;
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int ret;
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mutex_lock(&cpuset_mutex);
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ret = -ENOSPC;
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if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
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return -ENOSPC;
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goto out_unlock;
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cgroup_taskset_for_each(task, cgrp, tset) {
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/*
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@ -1390,10 +1391,12 @@ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
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* set_cpus_allowed_ptr() on all attached tasks before
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* cpus_allowed may be changed.
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*/
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ret = -EINVAL;
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if (task->flags & PF_THREAD_BOUND)
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return -EINVAL;
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if ((ret = security_task_setscheduler(task)))
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return ret;
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goto out_unlock;
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ret = security_task_setscheduler(task);
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if (ret)
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goto out_unlock;
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}
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/*
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@ -1401,18 +1404,22 @@ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
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* changes which zero cpus/mems_allowed.
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*/
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cs->attach_in_progress++;
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return 0;
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ret = 0;
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out_unlock:
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mutex_unlock(&cpuset_mutex);
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return ret;
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}
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static void cpuset_cancel_attach(struct cgroup *cgrp,
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struct cgroup_taskset *tset)
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{
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mutex_lock(&cpuset_mutex);
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cgroup_cs(cgrp)->attach_in_progress--;
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mutex_unlock(&cpuset_mutex);
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}
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/*
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* Protected by cgroup_mutex. cpus_attach is used only by cpuset_attach()
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* Protected by cpuset_mutex. cpus_attach is used only by cpuset_attach()
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* but we can't allocate it dynamically there. Define it global and
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* allocate from cpuset_init().
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*/
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@ -1420,7 +1427,7 @@ static cpumask_var_t cpus_attach;
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static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
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{
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/* static bufs protected by cgroup_mutex */
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/* static bufs protected by cpuset_mutex */
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static nodemask_t cpuset_attach_nodemask_from;
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static nodemask_t cpuset_attach_nodemask_to;
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struct mm_struct *mm;
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@ -1430,6 +1437,8 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
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struct cpuset *cs = cgroup_cs(cgrp);
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struct cpuset *oldcs = cgroup_cs(oldcgrp);
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mutex_lock(&cpuset_mutex);
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/* prepare for attach */
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if (cs == &top_cpuset)
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cpumask_copy(cpus_attach, cpu_possible_mask);
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@ -1473,6 +1482,8 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
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*/
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if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
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schedule_cpuset_propagate_hotplug(cs);
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mutex_unlock(&cpuset_mutex);
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}
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/* The various types of files and directories in a cpuset file system */
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@ -1494,12 +1505,13 @@ typedef enum {
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static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
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{
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int retval = 0;
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struct cpuset *cs = cgroup_cs(cgrp);
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cpuset_filetype_t type = cft->private;
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int retval = -ENODEV;
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if (!cgroup_lock_live_group(cgrp))
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return -ENODEV;
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mutex_lock(&cpuset_mutex);
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if (!is_cpuset_online(cs))
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goto out_unlock;
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switch (type) {
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case FILE_CPU_EXCLUSIVE:
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@ -1533,18 +1545,20 @@ static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
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retval = -EINVAL;
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break;
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}
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cgroup_unlock();
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out_unlock:
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mutex_unlock(&cpuset_mutex);
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return retval;
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}
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static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
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{
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int retval = 0;
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struct cpuset *cs = cgroup_cs(cgrp);
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cpuset_filetype_t type = cft->private;
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int retval = -ENODEV;
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if (!cgroup_lock_live_group(cgrp))
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return -ENODEV;
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mutex_lock(&cpuset_mutex);
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if (!is_cpuset_online(cs))
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goto out_unlock;
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switch (type) {
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case FILE_SCHED_RELAX_DOMAIN_LEVEL:
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@ -1554,7 +1568,8 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
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retval = -EINVAL;
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break;
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}
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cgroup_unlock();
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out_unlock:
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mutex_unlock(&cpuset_mutex);
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return retval;
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}
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@ -1564,9 +1579,9 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
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static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
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const char *buf)
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{
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int retval = 0;
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struct cpuset *cs = cgroup_cs(cgrp);
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struct cpuset *trialcs;
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int retval = -ENODEV;
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/*
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* CPU or memory hotunplug may leave @cs w/o any execution
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@ -1586,13 +1601,14 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
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flush_work(&cpuset_hotplug_work);
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flush_workqueue(cpuset_propagate_hotplug_wq);
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|
||||
if (!cgroup_lock_live_group(cgrp))
|
||||
return -ENODEV;
|
||||
mutex_lock(&cpuset_mutex);
|
||||
if (!is_cpuset_online(cs))
|
||||
goto out_unlock;
|
||||
|
||||
trialcs = alloc_trial_cpuset(cs);
|
||||
if (!trialcs) {
|
||||
retval = -ENOMEM;
|
||||
goto out;
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
switch (cft->private) {
|
||||
@ -1608,8 +1624,8 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
|
||||
}
|
||||
|
||||
free_trial_cpuset(trialcs);
|
||||
out:
|
||||
cgroup_unlock();
|
||||
out_unlock:
|
||||
mutex_unlock(&cpuset_mutex);
|
||||
return retval;
|
||||
}
|
||||
|
||||
@ -1867,6 +1883,8 @@ static int cpuset_css_online(struct cgroup *cgrp)
|
||||
if (!parent)
|
||||
return 0;
|
||||
|
||||
mutex_lock(&cpuset_mutex);
|
||||
|
||||
set_bit(CS_ONLINE, &cs->flags);
|
||||
if (is_spread_page(parent))
|
||||
set_bit(CS_SPREAD_PAGE, &cs->flags);
|
||||
@ -1876,7 +1894,7 @@ static int cpuset_css_online(struct cgroup *cgrp)
|
||||
number_of_cpusets++;
|
||||
|
||||
if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags))
|
||||
return 0;
|
||||
goto out_unlock;
|
||||
|
||||
/*
|
||||
* Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is
|
||||
@ -1895,7 +1913,7 @@ static int cpuset_css_online(struct cgroup *cgrp)
|
||||
cpuset_for_each_child(tmp_cs, pos_cg, parent) {
|
||||
if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) {
|
||||
rcu_read_unlock();
|
||||
return 0;
|
||||
goto out_unlock;
|
||||
}
|
||||
}
|
||||
rcu_read_unlock();
|
||||
@ -1904,7 +1922,8 @@ static int cpuset_css_online(struct cgroup *cgrp)
|
||||
cs->mems_allowed = parent->mems_allowed;
|
||||
cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
|
||||
mutex_unlock(&callback_mutex);
|
||||
|
||||
out_unlock:
|
||||
mutex_unlock(&cpuset_mutex);
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -1912,8 +1931,7 @@ static void cpuset_css_offline(struct cgroup *cgrp)
|
||||
{
|
||||
struct cpuset *cs = cgroup_cs(cgrp);
|
||||
|
||||
/* css_offline is called w/o cgroup_mutex, grab it */
|
||||
cgroup_lock();
|
||||
mutex_lock(&cpuset_mutex);
|
||||
|
||||
if (is_sched_load_balance(cs))
|
||||
update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);
|
||||
@ -1921,7 +1939,7 @@ static void cpuset_css_offline(struct cgroup *cgrp)
|
||||
number_of_cpusets--;
|
||||
clear_bit(CS_ONLINE, &cs->flags);
|
||||
|
||||
cgroup_unlock();
|
||||
mutex_unlock(&cpuset_mutex);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -1996,7 +2014,9 @@ static void cpuset_do_move_task(struct task_struct *tsk,
|
||||
{
|
||||
struct cgroup *new_cgroup = scan->data;
|
||||
|
||||
cgroup_lock();
|
||||
cgroup_attach_task(new_cgroup, tsk);
|
||||
cgroup_unlock();
|
||||
}
|
||||
|
||||
/**
|
||||
@ -2004,7 +2024,7 @@ static void cpuset_do_move_task(struct task_struct *tsk,
|
||||
* @from: cpuset in which the tasks currently reside
|
||||
* @to: cpuset to which the tasks will be moved
|
||||
*
|
||||
* Called with cgroup_mutex held
|
||||
* Called with cpuset_mutex held
|
||||
* callback_mutex must not be held, as cpuset_attach() will take it.
|
||||
*
|
||||
* The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
|
||||
@ -2031,9 +2051,6 @@ static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to)
|
||||
* removing that CPU or node from all cpusets. If this removes the
|
||||
* last CPU or node from a cpuset, then move the tasks in the empty
|
||||
* cpuset to its next-highest non-empty parent.
|
||||
*
|
||||
* Called with cgroup_mutex held
|
||||
* callback_mutex must not be held, as cpuset_attach() will take it.
|
||||
*/
|
||||
static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
|
||||
{
|
||||
@ -2089,8 +2106,9 @@ static void cpuset_propagate_hotplug_workfn(struct work_struct *work)
|
||||
static cpumask_t off_cpus;
|
||||
static nodemask_t off_mems, tmp_mems;
|
||||
struct cpuset *cs = container_of(work, struct cpuset, hotplug_work);
|
||||
bool is_empty;
|
||||
|
||||
cgroup_lock();
|
||||
mutex_lock(&cpuset_mutex);
|
||||
|
||||
cpumask_andnot(&off_cpus, cs->cpus_allowed, top_cpuset.cpus_allowed);
|
||||
nodes_andnot(off_mems, cs->mems_allowed, top_cpuset.mems_allowed);
|
||||
@ -2112,10 +2130,18 @@ static void cpuset_propagate_hotplug_workfn(struct work_struct *work)
|
||||
update_tasks_nodemask(cs, &tmp_mems, NULL);
|
||||
}
|
||||
|
||||
if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
|
||||
remove_tasks_in_empty_cpuset(cs);
|
||||
is_empty = cpumask_empty(cs->cpus_allowed) ||
|
||||
nodes_empty(cs->mems_allowed);
|
||||
|
||||
cgroup_unlock();
|
||||
mutex_unlock(&cpuset_mutex);
|
||||
|
||||
/*
|
||||
* If @cs became empty, move tasks to the nearest ancestor with
|
||||
* execution resources. This is full cgroup operation which will
|
||||
* also call back into cpuset. Should be done outside any lock.
|
||||
*/
|
||||
if (is_empty)
|
||||
remove_tasks_in_empty_cpuset(cs);
|
||||
|
||||
/* the following may free @cs, should be the last operation */
|
||||
css_put(&cs->css);
|
||||
@ -2169,7 +2195,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
|
||||
bool cpus_updated, mems_updated;
|
||||
bool cpus_offlined, mems_offlined;
|
||||
|
||||
cgroup_lock();
|
||||
mutex_lock(&cpuset_mutex);
|
||||
|
||||
/* fetch the available cpus/mems and find out which changed how */
|
||||
cpumask_copy(&new_cpus, cpu_active_mask);
|
||||
@ -2211,7 +2237,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
|
||||
schedule_cpuset_propagate_hotplug(cs);
|
||||
}
|
||||
|
||||
cgroup_unlock();
|
||||
mutex_unlock(&cpuset_mutex);
|
||||
|
||||
/* wait for propagations to finish */
|
||||
flush_workqueue(cpuset_propagate_hotplug_wq);
|
||||
@ -2222,9 +2248,9 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
|
||||
cpumask_var_t *doms;
|
||||
int ndoms;
|
||||
|
||||
cgroup_lock();
|
||||
mutex_lock(&cpuset_mutex);
|
||||
ndoms = generate_sched_domains(&doms, &attr);
|
||||
cgroup_unlock();
|
||||
mutex_unlock(&cpuset_mutex);
|
||||
|
||||
partition_sched_domains(ndoms, doms, attr);
|
||||
}
|
||||
@ -2650,7 +2676,7 @@ void __cpuset_memory_pressure_bump(void)
|
||||
* - Used for /proc/<pid>/cpuset.
|
||||
* - No need to task_lock(tsk) on this tsk->cpuset reference, as it
|
||||
* doesn't really matter if tsk->cpuset changes after we read it,
|
||||
* and we take cgroup_mutex, keeping cpuset_attach() from changing it
|
||||
* and we take cpuset_mutex, keeping cpuset_attach() from changing it
|
||||
* anyway.
|
||||
*/
|
||||
static int proc_cpuset_show(struct seq_file *m, void *unused_v)
|
||||
@ -2673,7 +2699,7 @@ static int proc_cpuset_show(struct seq_file *m, void *unused_v)
|
||||
goto out_free;
|
||||
|
||||
retval = -EINVAL;
|
||||
cgroup_lock();
|
||||
mutex_lock(&cpuset_mutex);
|
||||
css = task_subsys_state(tsk, cpuset_subsys_id);
|
||||
retval = cgroup_path(css->cgroup, buf, PAGE_SIZE);
|
||||
if (retval < 0)
|
||||
@ -2681,7 +2707,7 @@ static int proc_cpuset_show(struct seq_file *m, void *unused_v)
|
||||
seq_puts(m, buf);
|
||||
seq_putc(m, '\n');
|
||||
out_unlock:
|
||||
cgroup_unlock();
|
||||
mutex_unlock(&cpuset_mutex);
|
||||
put_task_struct(tsk);
|
||||
out_free:
|
||||
kfree(buf);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user