Andrew Morton <[email protected]> writes:
> On Fri, 13 Apr 2007 17:02:01 +0400
> Oleg Nesterov <[email protected]> wrote:
>
>> If kernel_thread(kthread) succeeds, kthread() can not fail on its path to
>> complete(&create->started) + schedule(). After that it can't be woken because
>> nobody can see the new task yet. This means:
>>
>> - we don't need tasklist_lock for find_task_by_pid().
>>
>> - create_kthread() doesn't need to wait for create->started. Instead,
>> kthread_create() first waits for create->created to get the result of
>> kernel_thread(), then waits for create->started to synchronize with
>> kthread().
>
> Why don't we need tasklist_lock for find_task_by_pid()? I'd have though that
> we'd at least need rcu_read_lock(), and I'm not sure that the implicit
> understanding of pid-management internals here is a great idea.
We need rcu_read_lock(). Or else something could permute the pid hash table
and get us into trouble.
Eric
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
