From: Oleg Nesterov This patch moves __unhash_process() call from realease_task() to __exit_signal(), so __detach_pid() is called with ->siglock held. This means we don't need tasklist_lock to iterate over thread group anymore: copy_process() was already changed to do attach_pid() under ->siglock. Eric's "pidhash-kill-switch_exec_pids.patch" from -mm changed de_thread() so it doesn't touch PIDTYPE_TGID. NOTE: de_thread() still needs some attention. It still changes task->pid lockless. Taking ->sighand.siglock here allows to do more tasklist_lock removals. Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton --- kernel/exit.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff -puN kernel/exit.c~do-__unhash_process-under-siglock kernel/exit.c --- 25/kernel/exit.c~do-__unhash_process-under-siglock Wed Feb 22 16:41:32 2006 +++ 25-akpm/kernel/exit.c Wed Feb 22 16:41:32 2006 @@ -110,6 +110,8 @@ static void __exit_signal(struct task_st sig = NULL; /* Marker for below. */ } + __unhash_process(tsk); + tsk->signal = NULL; cleanup_sighand(tsk); spin_unlock(&sighand->siglock); @@ -138,8 +140,6 @@ repeat: BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children)); __exit_signal(p); - __unhash_process(p); - /* * If we are the last non-leader member of the thread * group, and the leader is zombie, then notify the _