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cgroup/freezer: Add cgroup CGRP_FROZEN flag update helper

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Add help to update cgroup CGRP_FROZEN flag. Both cgroup_propagate_frozen
and cgroup_update_frozen functions update CGRP_FROZEN flag, this makes
code concise.

Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Chen Ridong 2024-10-22 11:49:46 +00:00 committed by Tejun Heo
parent ee1251fc0c
commit 16e83007cd
1 changed files with 32 additions and 35 deletions
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67
kernel/cgroup/freezer.c
View File

@ -8,6 +8,28 @@
#include <trace/events/cgroup.h>
/*
* Update CGRP_FROZEN of cgroup.flag
* Return true if flags is updated; false if flags has no change
*/
static bool cgroup_update_frozen_flag(struct cgroup *cgrp, bool frozen)
{
lockdep_assert_held(&css_set_lock);
/* Already there? */
if (test_bit(CGRP_FROZEN, &cgrp->flags) == frozen)
return false;
if (frozen)
set_bit(CGRP_FROZEN, &cgrp->flags);
else
clear_bit(CGRP_FROZEN, &cgrp->flags);
cgroup_file_notify(&cgrp->events_file);
TRACE_CGROUP_PATH(notify_frozen, cgrp, frozen);
return true;
}
/*
* Propagate the cgroup frozen state upwards by the cgroup tree.
*/
@ -24,24 +46,16 @@ static void cgroup_propagate_frozen(struct cgroup *cgrp, bool frozen)
while ((cgrp = cgroup_parent(cgrp))) {
if (frozen) {
cgrp->freezer.nr_frozen_descendants += desc;
if (!test_bit(CGRP_FROZEN, &cgrp->flags) &&
test_bit(CGRP_FREEZE, &cgrp->flags) &&
cgrp->freezer.nr_frozen_descendants ==
cgrp->nr_descendants) {
set_bit(CGRP_FROZEN, &cgrp->flags);
cgroup_file_notify(&cgrp->events_file);
TRACE_CGROUP_PATH(notify_frozen, cgrp, 1);
desc++;
}
if (!test_bit(CGRP_FREEZE, &cgrp->flags) ||
(cgrp->freezer.nr_frozen_descendants !=
cgrp->nr_descendants))
continue;
} else {
cgrp->freezer.nr_frozen_descendants -= desc;
if (test_bit(CGRP_FROZEN, &cgrp->flags)) {
clear_bit(CGRP_FROZEN, &cgrp->flags);
cgroup_file_notify(&cgrp->events_file);
TRACE_CGROUP_PATH(notify_frozen, cgrp, 0);
desc++;
}
}
if (cgroup_update_frozen_flag(cgrp, frozen))
desc++;
}
}
@ -53,8 +67,6 @@ void cgroup_update_frozen(struct cgroup *cgrp)
{
bool frozen;
lockdep_assert_held(&css_set_lock);
/*
* If the cgroup has to be frozen (CGRP_FREEZE bit set),
* and all tasks are frozen and/or stopped, let's consider
@ -63,24 +75,9 @@ void cgroup_update_frozen(struct cgroup *cgrp)
frozen = test_bit(CGRP_FREEZE, &cgrp->flags) &&
cgrp->freezer.nr_frozen_tasks == __cgroup_task_count(cgrp);
if (frozen) {
/* Already there? */
if (test_bit(CGRP_FROZEN, &cgrp->flags))
return;
set_bit(CGRP_FROZEN, &cgrp->flags);
} else {
/* Already there? */
if (!test_bit(CGRP_FROZEN, &cgrp->flags))
return;
clear_bit(CGRP_FROZEN, &cgrp->flags);
}
cgroup_file_notify(&cgrp->events_file);
TRACE_CGROUP_PATH(notify_frozen, cgrp, frozen);
/* Update the state of ancestor cgroups. */
cgroup_propagate_frozen(cgrp, frozen);
/* If flags is updated, update the state of ancestor cgroups. */
if (cgroup_update_frozen_flag(cgrp, frozen))
cgroup_propagate_frozen(cgrp, frozen);
}
/*