cpuset: use css_task_iter_start/next/end() instead of css_scan_tasks()
Now that css_task_iter_start/next_end() supports blocking while iterating, there's no reason to use css_scan_tasks() which is more cumbersome to use and scheduled to be removed. Convert all css_scan_tasks() usages in cpuset to css_task_iter_start/next/end(). This simplifies the code by removing heap allocation and callbacks. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>wifi-calibration
Tejun Heo
parent
96d365e0b8
commit
d66393e54e
186
kernel/cpuset.c
186
kernel/cpuset.c
|
|
@ -828,56 +828,37 @@ static struct cpuset *effective_nodemask_cpuset(struct cpuset *cs)
|
|||
return cs;
|
||||
}
|
||||
|
||||
/**
|
||||
* cpuset_change_cpumask - make a task's cpus_allowed the same as its cpuset's
|
||||
* @tsk: task to test
|
||||
* @data: cpuset to @tsk belongs to
|
||||
*
|
||||
* Called by css_scan_tasks() for each task in a cgroup whose cpus_allowed
|
||||
* mask needs to be changed.
|
||||
*
|
||||
* We don't need to re-check for the cgroup/cpuset membership, since we're
|
||||
* holding cpuset_mutex at this point.
|
||||
*/
|
||||
static void cpuset_change_cpumask(struct task_struct *tsk, void *data)
|
||||
{
|
||||
struct cpuset *cs = data;
|
||||
struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
|
||||
|
||||
set_cpus_allowed_ptr(tsk, cpus_cs->cpus_allowed);
|
||||
}
|
||||
|
||||
/**
|
||||
* update_tasks_cpumask - Update the cpumasks of tasks in the cpuset.
|
||||
* @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
|
||||
* @heap: if NULL, defer allocating heap memory to css_scan_tasks()
|
||||
*
|
||||
* Called with cpuset_mutex held
|
||||
*
|
||||
* The css_scan_tasks() function will scan all the tasks in a cgroup,
|
||||
* calling callback functions for each.
|
||||
*
|
||||
* No return value. It's guaranteed that css_scan_tasks() always returns 0
|
||||
* if @heap != NULL.
|
||||
* Iterate through each task of @cs updating its cpus_allowed to the
|
||||
* effective cpuset's. As this function is called with cpuset_mutex held,
|
||||
* cpuset membership stays stable.
|
||||
*/
|
||||
static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap)
|
||||
static void update_tasks_cpumask(struct cpuset *cs)
|
||||
{
|
||||
css_scan_tasks(&cs->css, NULL, cpuset_change_cpumask, cs, heap);
|
||||
struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
|
||||
struct css_task_iter it;
|
||||
struct task_struct *task;
|
||||
|
||||
css_task_iter_start(&cs->css, &it);
|
||||
while ((task = css_task_iter_next(&it)))
|
||||
set_cpus_allowed_ptr(task, cpus_cs->cpus_allowed);
|
||||
css_task_iter_end(&it);
|
||||
}
|
||||
|
||||
/*
|
||||
* update_tasks_cpumask_hier - Update the cpumasks of tasks in the hierarchy.
|
||||
* @root_cs: the root cpuset of the hierarchy
|
||||
* @update_root: update root cpuset or not?
|
||||
* @heap: the heap used by css_scan_tasks()
|
||||
*
|
||||
* This will update cpumasks of tasks in @root_cs and all other empty cpusets
|
||||
* which take on cpumask of @root_cs.
|
||||
*
|
||||
* Called with cpuset_mutex held
|
||||
*/
|
||||
static void update_tasks_cpumask_hier(struct cpuset *root_cs,
|
||||
bool update_root, struct ptr_heap *heap)
|
||||
static void update_tasks_cpumask_hier(struct cpuset *root_cs, bool update_root)
|
||||
{
|
||||
struct cpuset *cp;
|
||||
struct cgroup_subsys_state *pos_css;
|
||||
|
|
@ -898,7 +879,7 @@ static void update_tasks_cpumask_hier(struct cpuset *root_cs,
|
|||
continue;
|
||||
rcu_read_unlock();
|
||||
|
||||
update_tasks_cpumask(cp, heap);
|
||||
update_tasks_cpumask(cp);
|
||||
|
||||
rcu_read_lock();
|
||||
css_put(&cp->css);
|
||||
|
|
@ -914,7 +895,6 @@ static void update_tasks_cpumask_hier(struct cpuset *root_cs,
|
|||
static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
|
||||
const char *buf)
|
||||
{
|
||||
struct ptr_heap heap;
|
||||
int retval;
|
||||
int is_load_balanced;
|
||||
|
||||
|
|
@ -947,19 +927,13 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
|
|||
if (retval < 0)
|
||||
return retval;
|
||||
|
||||
retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
|
||||
if (retval)
|
||||
return retval;
|
||||
|
||||
is_load_balanced = is_sched_load_balance(trialcs);
|
||||
|
||||
mutex_lock(&callback_mutex);
|
||||
cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
|
||||
mutex_unlock(&callback_mutex);
|
||||
|
||||
update_tasks_cpumask_hier(cs, true, &heap);
|
||||
|
||||
heap_free(&heap);
|
||||
update_tasks_cpumask_hier(cs, true);
|
||||
|
||||
if (is_load_balanced)
|
||||
rebuild_sched_domains_locked();
|
||||
|
|
@ -1052,53 +1026,22 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk,
|
|||
task_unlock(tsk);
|
||||
}
|
||||
|
||||
struct cpuset_change_nodemask_arg {
|
||||
struct cpuset *cs;
|
||||
nodemask_t *newmems;
|
||||
};
|
||||
|
||||
/*
|
||||
* Update task's mems_allowed and rebind its mempolicy and vmas' mempolicy
|
||||
* of it to cpuset's new mems_allowed, and migrate pages to new nodes if
|
||||
* memory_migrate flag is set. Called with cpuset_mutex held.
|
||||
*/
|
||||
static void cpuset_change_nodemask(struct task_struct *p, void *data)
|
||||
{
|
||||
struct cpuset_change_nodemask_arg *arg = data;
|
||||
struct cpuset *cs = arg->cs;
|
||||
struct mm_struct *mm;
|
||||
int migrate;
|
||||
|
||||
cpuset_change_task_nodemask(p, arg->newmems);
|
||||
|
||||
mm = get_task_mm(p);
|
||||
if (!mm)
|
||||
return;
|
||||
|
||||
migrate = is_memory_migrate(cs);
|
||||
|
||||
mpol_rebind_mm(mm, &cs->mems_allowed);
|
||||
if (migrate)
|
||||
cpuset_migrate_mm(mm, &cs->old_mems_allowed, arg->newmems);
|
||||
mmput(mm);
|
||||
}
|
||||
|
||||
static void *cpuset_being_rebound;
|
||||
|
||||
/**
|
||||
* update_tasks_nodemask - Update the nodemasks of tasks in the cpuset.
|
||||
* @cs: the cpuset in which each task's mems_allowed mask needs to be changed
|
||||
* @heap: if NULL, defer allocating heap memory to css_scan_tasks()
|
||||
*
|
||||
* Called with cpuset_mutex held. No return value. It's guaranteed that
|
||||
* css_scan_tasks() always returns 0 if @heap != NULL.
|
||||
* Iterate through each task of @cs updating its mems_allowed to the
|
||||
* effective cpuset's. As this function is called with cpuset_mutex held,
|
||||
* cpuset membership stays stable.
|
||||
*/
|
||||
static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
|
||||
static void update_tasks_nodemask(struct cpuset *cs)
|
||||
{
|
||||
static nodemask_t newmems; /* protected by cpuset_mutex */
|
||||
struct cpuset *mems_cs = effective_nodemask_cpuset(cs);
|
||||
struct cpuset_change_nodemask_arg arg = { .cs = cs,
|
||||
.newmems = &newmems };
|
||||
struct css_task_iter it;
|
||||
struct task_struct *task;
|
||||
|
||||
cpuset_being_rebound = cs; /* causes mpol_dup() rebind */
|
||||
|
||||
|
|
@ -1114,7 +1057,25 @@ static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
|
|||
* It's ok if we rebind the same mm twice; mpol_rebind_mm()
|
||||
* is idempotent. Also migrate pages in each mm to new nodes.
|
||||
*/
|
||||
css_scan_tasks(&cs->css, NULL, cpuset_change_nodemask, &arg, heap);
|
||||
css_task_iter_start(&cs->css, &it);
|
||||
while ((task = css_task_iter_next(&it))) {
|
||||
struct mm_struct *mm;
|
||||
bool migrate;
|
||||
|
||||
cpuset_change_task_nodemask(task, &newmems);
|
||||
|
||||
mm = get_task_mm(task);
|
||||
if (!mm)
|
||||
continue;
|
||||
|
||||
migrate = is_memory_migrate(cs);
|
||||
|
||||
mpol_rebind_mm(mm, &cs->mems_allowed);
|
||||
if (migrate)
|
||||
cpuset_migrate_mm(mm, &cs->old_mems_allowed, &newmems);
|
||||
mmput(mm);
|
||||
}
|
||||
css_task_iter_end(&it);
|
||||
|
||||
/*
|
||||
* All the tasks' nodemasks have been updated, update
|
||||
|
|
@ -1130,15 +1091,13 @@ static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
|
|||
* update_tasks_nodemask_hier - Update the nodemasks of tasks in the hierarchy.
|
||||
* @cs: the root cpuset of the hierarchy
|
||||
* @update_root: update the root cpuset or not?
|
||||
* @heap: the heap used by css_scan_tasks()
|
||||
*
|
||||
* This will update nodemasks of tasks in @root_cs and all other empty cpusets
|
||||
* which take on nodemask of @root_cs.
|
||||
*
|
||||
* Called with cpuset_mutex held
|
||||
*/
|
||||
static void update_tasks_nodemask_hier(struct cpuset *root_cs,
|
||||
bool update_root, struct ptr_heap *heap)
|
||||
static void update_tasks_nodemask_hier(struct cpuset *root_cs, bool update_root)
|
||||
{
|
||||
struct cpuset *cp;
|
||||
struct cgroup_subsys_state *pos_css;
|
||||
|
|
@ -1159,7 +1118,7 @@ static void update_tasks_nodemask_hier(struct cpuset *root_cs,
|
|||
continue;
|
||||
rcu_read_unlock();
|
||||
|
||||
update_tasks_nodemask(cp, heap);
|
||||
update_tasks_nodemask(cp);
|
||||
|
||||
rcu_read_lock();
|
||||
css_put(&cp->css);
|
||||
|
|
@ -1184,7 +1143,6 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
|
|||
const char *buf)
|
||||
{
|
||||
int retval;
|
||||
struct ptr_heap heap;
|
||||
|
||||
/*
|
||||
* top_cpuset.mems_allowed tracks node_stats[N_MEMORY];
|
||||
|
|
@ -1223,17 +1181,11 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
|
|||
if (retval < 0)
|
||||
goto done;
|
||||
|
||||
retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
|
||||
if (retval < 0)
|
||||
goto done;
|
||||
|
||||
mutex_lock(&callback_mutex);
|
||||
cs->mems_allowed = trialcs->mems_allowed;
|
||||
mutex_unlock(&callback_mutex);
|
||||
|
||||
update_tasks_nodemask_hier(cs, true, &heap);
|
||||
|
||||
heap_free(&heap);
|
||||
update_tasks_nodemask_hier(cs, true);
|
||||
done:
|
||||
return retval;
|
||||
}
|
||||
|
|
@ -1260,39 +1212,23 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val)
|
|||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* cpuset_change_flag - make a task's spread flags the same as its cpuset's
|
||||
* @tsk: task to be updated
|
||||
* @data: cpuset to @tsk belongs to
|
||||
*
|
||||
* Called by css_scan_tasks() for each task in a cgroup.
|
||||
*
|
||||
* We don't need to re-check for the cgroup/cpuset membership, since we're
|
||||
* holding cpuset_mutex at this point.
|
||||
*/
|
||||
static void cpuset_change_flag(struct task_struct *tsk, void *data)
|
||||
{
|
||||
struct cpuset *cs = data;
|
||||
|
||||
cpuset_update_task_spread_flag(cs, tsk);
|
||||
}
|
||||
|
||||
/**
|
||||
* update_tasks_flags - update the spread flags of tasks in the cpuset.
|
||||
* @cs: the cpuset in which each task's spread flags needs to be changed
|
||||
* @heap: if NULL, defer allocating heap memory to css_scan_tasks()
|
||||
*
|
||||
* Called with cpuset_mutex held
|
||||
*
|
||||
* The css_scan_tasks() function will scan all the tasks in a cgroup,
|
||||
* calling callback functions for each.
|
||||
*
|
||||
* No return value. It's guaranteed that css_scan_tasks() always returns 0
|
||||
* if @heap != NULL.
|
||||
* Iterate through each task of @cs updating its spread flags. As this
|
||||
* function is called with cpuset_mutex held, cpuset membership stays
|
||||
* stable.
|
||||
*/
|
||||
static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap)
|
||||
static void update_tasks_flags(struct cpuset *cs)
|
||||
{
|
||||
css_scan_tasks(&cs->css, NULL, cpuset_change_flag, cs, heap);
|
||||
struct css_task_iter it;
|
||||
struct task_struct *task;
|
||||
|
||||
css_task_iter_start(&cs->css, &it);
|
||||
while ((task = css_task_iter_next(&it)))
|
||||
cpuset_update_task_spread_flag(cs, task);
|
||||
css_task_iter_end(&it);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -1310,7 +1246,6 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
|
|||
struct cpuset *trialcs;
|
||||
int balance_flag_changed;
|
||||
int spread_flag_changed;
|
||||
struct ptr_heap heap;
|
||||
int err;
|
||||
|
||||
trialcs = alloc_trial_cpuset(cs);
|
||||
|
|
@ -1326,10 +1261,6 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
|
|||
if (err < 0)
|
||||
goto out;
|
||||
|
||||
err = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
|
||||
if (err < 0)
|
||||
goto out;
|
||||
|
||||
balance_flag_changed = (is_sched_load_balance(cs) !=
|
||||
is_sched_load_balance(trialcs));
|
||||
|
||||
|
|
@ -1344,8 +1275,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
|
|||
rebuild_sched_domains_locked();
|
||||
|
||||
if (spread_flag_changed)
|
||||
update_tasks_flags(cs, &heap);
|
||||
heap_free(&heap);
|
||||
update_tasks_flags(cs);
|
||||
out:
|
||||
free_trial_cpuset(trialcs);
|
||||
return err;
|
||||
|
|
@ -2138,7 +2068,7 @@ retry:
|
|||
*/
|
||||
if ((sane && cpumask_empty(cs->cpus_allowed)) ||
|
||||
(!cpumask_empty(&off_cpus) && !cpumask_empty(cs->cpus_allowed)))
|
||||
update_tasks_cpumask(cs, NULL);
|
||||
update_tasks_cpumask(cs);
|
||||
|
||||
mutex_lock(&callback_mutex);
|
||||
nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems);
|
||||
|
|
@ -2152,7 +2082,7 @@ retry:
|
|||
*/
|
||||
if ((sane && nodes_empty(cs->mems_allowed)) ||
|
||||
(!nodes_empty(off_mems) && !nodes_empty(cs->mems_allowed)))
|
||||
update_tasks_nodemask(cs, NULL);
|
||||
update_tasks_nodemask(cs);
|
||||
|
||||
is_empty = cpumask_empty(cs->cpus_allowed) ||
|
||||
nodes_empty(cs->mems_allowed);
|
||||
|
|
@ -2214,7 +2144,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
|
|||
mutex_lock(&callback_mutex);
|
||||
top_cpuset.mems_allowed = new_mems;
|
||||
mutex_unlock(&callback_mutex);
|
||||
update_tasks_nodemask(&top_cpuset, NULL);
|
||||
update_tasks_nodemask(&top_cpuset);
|
||||
}
|
||||
|
||||
mutex_unlock(&cpuset_mutex);
|
||||
|
|
|
|||
Loading…
Reference in New Issue