diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/fork.c | 2 | ||||
| -rw-r--r-- | kernel/sched/core.c | 22 |
2 files changed, 15 insertions, 9 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 65113a304518..7febf4c2889e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1586,7 +1586,6 @@ static int copy_mm(u64 clone_flags, struct task_struct *tsk) tsk->mm = mm; tsk->active_mm = mm; - sched_mm_cid_fork(tsk); return 0; } @@ -2498,7 +2497,6 @@ bad_fork_cleanup_namespaces: exit_nsproxy_namespaces(p); bad_fork_cleanup_mm: if (p->mm) { - sched_mm_cid_exit(p); mm_clear_owner(p->mm, p); mmput(p->mm); } diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b7f77c165a6e..d25427855b5d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4729,8 +4729,11 @@ void sched_cancel_fork(struct task_struct *p) scx_cancel_fork(p); } +static void sched_mm_cid_fork(struct task_struct *t); + void sched_post_fork(struct task_struct *p) { + sched_mm_cid_fork(p); uclamp_post_fork(p); scx_post_fork(p); } @@ -10646,12 +10649,13 @@ static void mm_cid_do_fixup_tasks_to_cpus(struct mm_struct *mm) * possible switch back to per task mode happens either in the * deferred handler function or in the next fork()/exit(). * - * The caller has already transferred. The newly incoming task is - * already accounted for, but not yet visible. + * The caller has already transferred so remove it from the users + * count. The incoming task is already visible and has mm_cid.active, + * but has task::mm_cid::cid == UNSET. Still it needs to be accounted + * for. Concurrent fork()s might add more threads, but all of them have + * task::mm_cid::active = 0, so they don't affect the accounting here. */ - users = mm->mm_cid.users - 2; - if (!users) - return; + users = mm->mm_cid.users - 1; guard(rcu)(); for_other_threads(current, t) { @@ -10688,12 +10692,15 @@ static bool sched_mm_cid_add_user(struct task_struct *t, struct mm_struct *mm) return mm_update_max_cids(mm); } -void sched_mm_cid_fork(struct task_struct *t) +static void sched_mm_cid_fork(struct task_struct *t) { struct mm_struct *mm = t->mm; bool percpu; - WARN_ON_ONCE(!mm || t->mm_cid.cid != MM_CID_UNSET); + if (!mm) + return; + + WARN_ON_ONCE(t->mm_cid.cid != MM_CID_UNSET); guard(mutex)(&mm->mm_cid.mutex); scoped_guard(raw_spinlock_irq, &mm->mm_cid.lock) { @@ -10885,6 +10892,7 @@ void mm_init_cid(struct mm_struct *mm, struct task_struct *p) } #else /* CONFIG_SCHED_MM_CID */ static inline void mm_update_cpus_allowed(struct mm_struct *mm, const struct cpumask *affmsk) { } +static inline void sched_mm_cid_fork(struct task_struct *t) { } #endif /* !CONFIG_SCHED_MM_CID */ static DEFINE_PER_CPU(struct sched_change_ctx, sched_change_ctx); |