Messages in this thread | | | Date | Mon, 8 Feb 2010 18:16:44 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH] Update comment on find_task_by_pid_ns |
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On 02/08, Thomas Gleixner wrote: > > On Mon, 8 Feb 2010, Oleg Nesterov wrote: > > > IOW, if we change copy_process() > > > > --- kernel/fork.c > > +++ kernel/fork.c > > @@ -1304,8 +1304,11 @@ static struct task_struct *copy_process( > > return p; > > > > bad_fork_free_pid: > > - if (pid != &init_struct_pid) > > + if (pid != &init_struct_pid) { > > + read_lock(&tasklist_lock); > > free_pid(pid); > > + read_unlock(&tasklist_lock); > > + } > > bad_fork_cleanup_io: > > if (p->io_context) > > exit_io_context(p); > > > > then find_task_by_pid_ns/etc could be used under tasklist safely even > > with PREEMPT_RCU. > > We try to get rid of the read_lock sites of tasklist_lock, so please > let's not think about adding more :)
Yes, yes, I agree. I didn't mean this patch makes sense.
Oleg.
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