Commit e713d0da authored by Sukadev Bhattiprolu's avatar Sukadev Bhattiprolu Committed by Linus Torvalds
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attach_pid() with struct pid parameter

attach_pid() currently takes a pid_t and then uses find_pid() to find the
corresponding struct pid.  Sometimes we already have the struct pid.  We can
then skip find_pid() if attach_pid() were to take a struct pid parameter.
Signed-off-by: default avatarSukadev Bhattiprolu <>
Cc: Cedric Le Goater <>
Cc: Dave Hansen <>
Cc: Serge Hallyn <>
Cc: <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 4ac24b3b
......@@ -702,7 +702,7 @@ static int de_thread(struct task_struct *tsk)
detach_pid(tsk, PIDTYPE_PID);
tsk->pid = leader->pid;
attach_pid(tsk, PIDTYPE_PID, tsk->pid);
attach_pid(tsk, PIDTYPE_PID, find_pid(tsk->pid));
transfer_pid(leader, tsk, PIDTYPE_PGID);
transfer_pid(leader, tsk, PIDTYPE_SID);
list_replace_rcu(&leader->tasks, &tsk->tasks);
......@@ -76,8 +76,7 @@ extern struct pid *get_task_pid(struct task_struct *task, enum pid_type type);
* write-held.
extern int FASTCALL(attach_pid(struct task_struct *task,
enum pid_type type, int nr));
enum pid_type type, struct pid *pid));
extern void FASTCALL(detach_pid(struct task_struct *task, enum pid_type));
extern void FASTCALL(transfer_pid(struct task_struct *old,
struct task_struct *new, enum pid_type));
......@@ -302,12 +302,12 @@ void __set_special_pids(pid_t session, pid_t pgrp)
if (process_session(curr) != session) {
detach_pid(curr, PIDTYPE_SID);
set_signal_session(curr->signal, session);
attach_pid(curr, PIDTYPE_SID, session);
attach_pid(curr, PIDTYPE_SID, find_pid(session));
if (process_group(curr) != pgrp) {
detach_pid(curr, PIDTYPE_PGID);
curr->signal->pgrp = pgrp;
attach_pid(curr, PIDTYPE_PGID, pgrp);
attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp));
......@@ -1249,16 +1249,19 @@ static struct task_struct *copy_process(unsigned long clone_flags,
__ptrace_link(p, current->parent);
if (thread_group_leader(p)) {
pid_t pgid = process_group(current);
pid_t sid = process_session(current);
p->signal->tty = current->signal->tty;
p->signal->pgrp = process_group(current);
p->signal->pgrp = pgid;
set_signal_session(p->signal, process_session(current));
attach_pid(p, PIDTYPE_PGID, process_group(p));
attach_pid(p, PIDTYPE_SID, process_session(p));
attach_pid(p, PIDTYPE_PGID, find_pid(pgid));
attach_pid(p, PIDTYPE_SID, find_pid(sid));
list_add_tail_rcu(&p->tasks, &init_task.tasks);
attach_pid(p, PIDTYPE_PID, p->pid);
attach_pid(p, PIDTYPE_PID, find_pid(p->pid));
......@@ -247,13 +247,16 @@ struct pid * fastcall find_pid(int nr)
int fastcall attach_pid(struct task_struct *task, enum pid_type type, int nr)
* attach_pid() must be called with the tasklist_lock write-held.
int fastcall attach_pid(struct task_struct *task, enum pid_type type,
struct pid *pid)
struct pid_link *link;
struct pid *pid;
link = &task->pids[type];
link->pid = pid = find_pid(nr);
link->pid = pid;
hlist_add_head_rcu(&link->node, &pid->tasks[type]);
return 0;
......@@ -1488,7 +1488,7 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
if (process_group(p) != pgid) {
detach_pid(p, PIDTYPE_PGID);
p->signal->pgrp = pgid;
attach_pid(p, PIDTYPE_PGID, pgid);
attach_pid(p, PIDTYPE_PGID, find_pid(pgid));
err = 0;
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