From bf92370c035d5ed73a90927450c20a07adf08cfd Mon Sep 17 00:00:00 2001 From: Waiman Long Date: Thu, 8 Nov 2018 10:08:37 -0500 Subject: 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 Acked-by: Peter Zijlstra (Intel) Signed-off-by: Tejun Heo --- kernel/cgroup/cpuset.c | 110 ++++++++++++++++++++++++++++++++++--------------- 1 file changed, 77 insertions(+), 33 deletions(-) (limited to 'kernel/cgroup') diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 29a2bdc671fd..2ac9437ce8f1 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -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); -- cgit