Re: [PATCH] kill do_each_thread()

[Jiri Slaby]

On 18. 08. 23, 10:16, Oleg Nesterov wrote:
> On 08/18, Jiri Slaby wrote:
> > On 17. 08. 23, 18:37, Oleg Nesterov wrote:
> > > Eric has pointed out that we still have 3 users of do_each_thread().
> > > Change them to use for_each_process_thread() and kill this helper.
> >
> > Is there any change in behavior?
>
> No.
>
> Well, there is a subtle change, after do_each_thread/while_each_thread
> g == t == &init_task, while after for_each_process_thread() they both
> point to nowhere, but this doesn't matter.
>
> > Why is for_each_process_thread() better than do_each_thread()?
>
> Say, for_each_process_thread() is rcu safe, do_each_thread() is not.
>
> And certainly
>
> 	for_each_process_thread(p, t) {
> 		do_something(p, t);
> 	}
>
> looks better than
>
> 	do_each_thread(p, t) {
> 		do_something(p, t);
> 	} while_each_thread(p, t);
>
> And again, there are only 3 users of this awkward helper left.
> It should have been killed years ago and in fact I thought it
> had already been killed. It uses while_each_thread() which needs
> some changes.

Sounds like a perfect commit log now... Unless squashed to the patch, it 
will be Linked at least. Thanks for explanation.

--
js
suse labs