xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[PATCH] pids: kill PIDTYPE_TGID

Browse Source 
This patch kills PIDTYPE_TGID pid_type thus saving one hash table in
kernel/pid.c and speeding up subthreads create/destroy a bit.  It is also a
preparation for the further tref/pids rework.

This patch adds 'struct list_head thread_group' to 'struct task_struct'
instead.

We don't detach group leader from PIDTYPE_PID namespace until another
thread inherits it's ->pid == ->tgid, so we are safe wrt premature
free_pidmap(->tgid) call.

Currently there are no users of find_task_by_pid_type(PIDTYPE_TGID).
Should the need arise, we can use find_task_by_pid()->group_leader.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-By: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Oleg Nesterov
2006-03-28 16:11:25 -08:00
committed by Linus Torvalds
parent 88531f725b
commit 47e65328a7
4 changed files with 12 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
kernel/exit.c
View File

@@ -51,7 +51,6 @@ static void __unhash_process(struct task_struct *p)
{
nr_threads--;
detach_pid(p, PIDTYPE_PID);
detach_pid(p, PIDTYPE_TGID);
if (thread_group_leader(p)) {
detach_pid(p, PIDTYPE_PGID);
detach_pid(p, PIDTYPE_SID);
@@ -59,7 +58,7 @@ static void __unhash_process(struct task_struct *p)
list_del_init(&p->tasks);
__get_cpu_var(process_counts)--;
}
list_del_rcu(&p->thread_group);
remove_parent(p);
}
@@ -964,13 +963,6 @@ asmlinkage long sys_exit(int error_code)
do_exit((error_code&0xff)<<8);
}
task_t fastcall *next_thread(const task_t *p)
{
return pid_task(p->pids[PIDTYPE_TGID].pid_list.next, PIDTYPE_TGID);
}
EXPORT_SYMBOL(next_thread);
/*
* Take down every thread in the group. This is called by fatal signals
* as well as by sys_exit_group (below).