From 7903f907a226058ed99f86e9924e082aea57fc45 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Thu, 6 Feb 2025 17:44:13 +0100 Subject: pid: perform free_pid() calls outside of tasklist_lock As the clone side already executes pid allocation with only pidmap_lock held, issuing free_pid() while still holding tasklist_lock exacerbates total hold time of the latter. More things may show up later which require initial clean up with the lock held and allow finishing without it. For that reason a struct to collect such work is added instead of merely passing the pid array. Reviewed-by: Oleg Nesterov Signed-off-by: Mateusz Guzik Link: https://lore.kernel.org/r/20250206164415.450051-5-mjguzik@gmail.com Acked-by: "Liam R. Howlett" Signed-off-by: Christian Brauner --- include/linux/pid.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/pid.h b/include/linux/pid.h index 98837a1ff0f3..311ecebd7d56 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -101,9 +101,9 @@ extern struct pid *get_task_pid(struct task_struct *task, enum pid_type type); * these helpers must be called with the tasklist_lock write-held. */ extern void attach_pid(struct task_struct *task, enum pid_type); -extern void detach_pid(struct task_struct *task, enum pid_type); -extern void change_pid(struct task_struct *task, enum pid_type, - struct pid *pid); +void detach_pid(struct pid **pids, struct task_struct *task, enum pid_type); +void change_pid(struct pid **pids, struct task_struct *task, enum pid_type, + struct pid *pid); extern void exchange_tids(struct task_struct *task, struct task_struct *old); extern void transfer_pid(struct task_struct *old, struct task_struct *new, enum pid_type); @@ -129,6 +129,7 @@ extern struct pid *find_ge_pid(int nr, struct pid_namespace *); extern struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid, size_t set_tid_size); extern void free_pid(struct pid *pid); +void free_pids(struct pid **pids); extern void disable_pid_allocation(struct pid_namespace *ns); /* -- cgit v1.2.3