Messages in this thread | | | Date | Wed, 29 Jan 2014 15:55:35 +0100 | From | Oleg Nesterov <> | Subject | Re: Do we really need curr_target in signal_struct ? |
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On 01/29, Rakib Mullick wrote: > > On Tue, Jan 28, 2014 at 10:43 PM, Oleg Nesterov <oleg@redhat.com> wrote: > > > But I guess ->curr_target was added exactly to avoid this loop if > > possible, assuming that wants_signal(->current_targer) should be > > likely true. Although perhaps this optimization is too simple. > > > Well, this code block will only hit when first check for wants_signal() > will miss,
Yes,
> that means we need to find some other thread of the group.
Yes,
> AFAIU, ->current_target is only a loop breaker to avoid infinite loop,
No. It caches the last result of "find a thread which can handle this group-wide signal".
> but - by using while_each_thread() we can remove it completely, thus > helps to get rid from maintaining it too.
... and remove the optimization above.
> I'll prepare a proper patch with you suggestions for reviewing.
I am not sure we want this patch. Once again, I do not know how much ->curr_target helps, and certainaly it can't help always. But you should not blindly remove it just because yes, sure, it is not strictly needed to find a wants_signal() thread.
Oleg.
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