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cpuset: Simply allocation and freeing of cpumasks 

The previous commit introduces a new subparts_cpus mask into the cpuset
data structure and a new tmpmasks structure.  Managing the allocation
and freeing of those cpumasks is becoming more complex.

So a number of helper functions are added to simplify and streamline
the management of those cpumasks. To make it simple, all the cpumasks
are now pre-cleared on allocation.

Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Waiman Long 2018-11-08 10:08:37 -05:00 committed by Tejun Heo
parent 58b7484250
commit bf92370c03
1 changed files with 77 additions and 33 deletions
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110
kernel/cgroup/cpuset.c
View File

@ -455,6 +455,65 @@ static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
is_mem_exclusive(p) <= is_mem_exclusive(q);
}
/**
* alloc_cpumasks - allocate three cpumasks for cpuset
* @cs: the cpuset that have cpumasks to be allocated.
* @tmp: the tmpmasks structure pointer
* Return: 0 if successful, -ENOMEM otherwise.
*
* Only one of the two input arguments should be non-NULL.
*/
static inline int alloc_cpumasks(struct cpuset *cs, struct tmpmasks *tmp)
{
cpumask_var_t *pmask1, *pmask2, *pmask3;
if (cs) {
pmask1 = &cs->cpus_allowed;
pmask2 = &cs->effective_cpus;
pmask3 = &cs->subparts_cpus;
} else {
pmask1 = &tmp->new_cpus;
pmask2 = &tmp->addmask;
pmask3 = &tmp->delmask;
}
if (!zalloc_cpumask_var(pmask1, GFP_KERNEL))
return -ENOMEM;
if (!zalloc_cpumask_var(pmask2, GFP_KERNEL))
goto free_one;
if (!zalloc_cpumask_var(pmask3, GFP_KERNEL))
goto free_two;
return 0;
free_two:
free_cpumask_var(*pmask2);
free_one:
free_cpumask_var(*pmask1);
return -ENOMEM;
}
/**
* free_cpumasks - free cpumasks in a tmpmasks structure
* @cs: the cpuset that have cpumasks to be free.
* @tmp: the tmpmasks structure pointer
*/
static inline void free_cpumasks(struct cpuset *cs, struct tmpmasks *tmp)
{
if (cs) {
free_cpumask_var(cs->cpus_allowed);
free_cpumask_var(cs->effective_cpus);
free_cpumask_var(cs->subparts_cpus);
}
if (tmp) {
free_cpumask_var(tmp->new_cpus);
free_cpumask_var(tmp->addmask);
free_cpumask_var(tmp->delmask);
}
}
/**
* alloc_trial_cpuset - allocate a trial cpuset
* @cs: the cpuset that the trial cpuset duplicates
@ -467,31 +526,24 @@ static struct cpuset *alloc_trial_cpuset(struct cpuset *cs)
if (!trial)
return NULL;
if (!alloc_cpumask_var(&trial->cpus_allowed, GFP_KERNEL))
goto free_cs;
if (!alloc_cpumask_var(&trial->effective_cpus, GFP_KERNEL))
goto free_cpus;
if (alloc_cpumasks(trial, NULL)) {
kfree(trial);
return NULL;
}
cpumask_copy(trial->cpus_allowed, cs->cpus_allowed);
cpumask_copy(trial->effective_cpus, cs->effective_cpus);
return trial;
free_cpus:
free_cpumask_var(trial->cpus_allowed);
free_cs:
kfree(trial);
return NULL;
}
/**
* free_trial_cpuset - free the trial cpuset
* @trial: the trial cpuset to be freed
* free_cpuset - free the cpuset
* @cs: the cpuset to be freed
*/
static void free_trial_cpuset(struct cpuset *trial)
static inline void free_cpuset(struct cpuset *cs)
{
free_cpumask_var(trial->effective_cpus);
free_cpumask_var(trial->cpus_allowed);
kfree(trial);
free_cpumasks(cs, NULL);
kfree(cs);
}
/*
@ -1385,7 +1437,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
if (spread_flag_changed)
update_tasks_flags(cs);
out:
free_trial_cpuset(trialcs);
free_cpuset(trialcs);
return err;
}
@ -1769,7 +1821,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
break;
}
free_trial_cpuset(trialcs);
free_cpuset(trialcs);
out_unlock:
mutex_unlock(&cpuset_mutex);
kernfs_unbreak_active_protection(of->kn);
@ -2024,26 +2076,19 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
cs = kzalloc(sizeof(*cs), GFP_KERNEL);
if (!cs)
return ERR_PTR(-ENOMEM);
if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL))
goto free_cs;
if (!alloc_cpumask_var(&cs->effective_cpus, GFP_KERNEL))
goto free_cpus;
if (alloc_cpumasks(cs, NULL)) {
kfree(cs);
return ERR_PTR(-ENOMEM);
}
set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
cpumask_clear(cs->cpus_allowed);
nodes_clear(cs->mems_allowed);
cpumask_clear(cs->effective_cpus);
nodes_clear(cs->effective_mems);
fmeter_init(&cs->fmeter);
cs->relax_domain_level = -1;
return &cs->css;
free_cpus:
free_cpumask_var(cs->cpus_allowed);
free_cs:
kfree(cs);
return ERR_PTR(-ENOMEM);
}
static int cpuset_css_online(struct cgroup_subsys_state *css)
@ -2134,9 +2179,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
{
struct cpuset *cs = css_cs(css);
free_cpumask_var(cs->effective_cpus);
free_cpumask_var(cs->cpus_allowed);
kfree(cs);
free_cpuset(cs);
}
static void cpuset_bind(struct cgroup_subsys_state *root_css)
@ -2200,6 +2243,7 @@ int __init cpuset_init(void)
BUG_ON(!alloc_cpumask_var(&top_cpuset.cpus_allowed, GFP_KERNEL));
BUG_ON(!alloc_cpumask_var(&top_cpuset.effective_cpus, GFP_KERNEL));
BUG_ON(!zalloc_cpumask_var(&top_cpuset.subparts_cpus, GFP_KERNEL));
cpumask_setall(top_cpuset.cpus_allowed);
nodes_setall(top_cpuset.mems_allowed);