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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-08-09 06:14:34 +02:00
Guopeng ZhangandTejun Heo
5dd74441cb
cpuset_can_attach() currently adds the bandwidth of all migrating
SCHED_DEADLINE tasks to sum_migrate_dl_bw. If the source and destination
cpuset effective CPU masks do not overlap, the whole sum is then
reserved in the destination root domain.
set_cpus_allowed_dl(), however, subtracts bandwidth from the source
root domain only when the affinity change really moves the task between
root domains. A DL task can move between cpusets that are still in the
same root domain, so including that task in sum_migrate_dl_bw can reserve
destination bandwidth without a matching source-side subtraction.
Share the root-domain move test with set_cpus_allowed_dl(). Keep
nr_migrate_dl_tasks counting all migrating deadline tasks for cpuset DL
task accounting, but add to sum_migrate_dl_bw only for tasks that need a
root-domain bandwidth move. Keep using the destination cpuset effective
CPU mask and leave the broader can_attach()/attach() transaction model
unchanged.
Fixes: 2ef269ef1a ("cgroup/cpuset: Free DL BW in case can_attach() fails")
Cc: stable@vger.kernel.org # v6.10+
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Reviewed-by: Waiman Long <longman@redhat.com>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
77 lines
2.2 KiB
C
77 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_SCHED_DEADLINE_H
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#define _LINUX_SCHED_DEADLINE_H
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/*
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* SCHED_DEADLINE tasks has negative priorities, reflecting
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* the fact that any of them has higher prio than RT and
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* NORMAL/BATCH tasks.
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*/
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#include <linux/sched.h>
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static inline bool dl_prio(int prio)
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{
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return unlikely(prio < MAX_DL_PRIO);
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}
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/*
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* Returns true if a task has a priority that belongs to DL class. PI-boosted
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* tasks will return true. Use dl_policy() to ignore PI-boosted tasks.
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*/
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static inline bool dl_task(struct task_struct *p)
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{
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return dl_prio(p->prio);
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}
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static inline bool dl_time_before(u64 a, u64 b)
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{
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return (s64)(a - b) < 0;
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}
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struct root_domain;
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extern void dl_add_task_root_domain(struct task_struct *p);
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extern void dl_clear_root_domain(struct root_domain *rd);
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extern void dl_clear_root_domain_cpu(int cpu);
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/*
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* Return whether moving DL task @p to @new_mask requires moving DL
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* bandwidth accounting between root domains. This helper is specific to
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* DL bandwidth move accounting semantics and is shared by
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* cpuset_can_attach() and set_cpus_allowed_dl() so both paths use the
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* same source root-domain test.
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*/
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extern bool dl_task_needs_bw_move(struct task_struct *p,
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const struct cpumask *new_mask);
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extern u64 dl_cookie;
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extern bool dl_bw_visited(int cpu, u64 cookie);
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static inline bool dl_server(struct sched_dl_entity *dl_se)
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{
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return dl_se->dl_server;
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}
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static inline struct task_struct *dl_task_of(struct sched_dl_entity *dl_se)
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{
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BUG_ON(dl_server(dl_se));
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return container_of(dl_se, struct task_struct, dl);
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}
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/*
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* Regarding the deadline, a task with implicit deadline has a relative
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* deadline == relative period. A task with constrained deadline has a
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* relative deadline <= relative period.
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*
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* We support constrained deadline tasks. However, there are some restrictions
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* applied only for tasks which do not have an implicit deadline. See
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* update_dl_entity() to know more about such restrictions.
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*
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* The dl_is_implicit() returns true if the task has an implicit deadline.
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*/
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static inline bool dl_is_implicit(struct sched_dl_entity *dl_se)
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{
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return dl_se->dl_deadline == dl_se->dl_period;
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}
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#endif /* _LINUX_SCHED_DEADLINE_H */
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