Messages in this thread |  | | Date | Sat, 07 Sep 2002 11:06:29 +0200 | From | Manfred Spraul <> | Subject | Re: [PATCH] pid_max hang again... |
| |
> As Manfred pointed out, pid allocation and inserting it into task > list should be atomic. But going by the range of pids available > in 2.5.33 (Linux made it 30-bits), it is unlikely that same pid > will be given to two processes, since last_pid is protected by > single lock. Right now there is quite a lot of code between get_pid and the insertion into the task list: copy mm, files, etc.
And just before the endless loop in get_pid(), there is only one pid left --> probability of getting the same pid again is high. If you fix the hang, you should fix the atomicity, too.
> If last_pid is within PID_MAX and max_pid_cross is set, this > pid might have been given to another process. So, goto the > corresponding hashlist and check for its existence. If no task > with given pid found, then get_pid is free to return pid as the > available pid.
Doesn't work: find_task_by_pid() only checks task->pid. But the result of get_pid mustn't be in use as a session or tgid value either
-- Manfred
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |