Re: [PATCH v3 0/2] tpm: add support for nonblocking operation

Tadeusz Struk
2018-06-21T01:24:41Z

On 06/20/2018 04:59 PM, James Bottomley wrote:
> I'm slightly surprised by this statement. I thought IoT Node.js
> runtimes (of which there are far too many, so I haven't looked at all
> of them) use libuv or one of the forks:
>
> http://libuv.org/
>
> As the basis for their I/O handling? While libuv can do polling for
> event driven interfaces it also support the worker thread model just as
> easily:
>
> http://docs.libuv.org/en/v1.x/threadpool.html

Yes, it does polling:
http://docs.libuv.org/en/v1.x/design.html#the-i-o-loop

>
>> Similarly embedded applications, which are basically just a single
>> threaded event loop, quite often don't use threads because of
>> resources constrains.
> It's hard for me, as a kernel developer, to imagine any embedded
> scenario using the Linux kernel that would not allow threads unless the
> writers simply didn't bother with synchronization: The kernel schedules
> at the threads level and can't be configured not to use them plus
> threads are inherently more lightweight than processes so they're a
> natural fit for resource constrained scenarios.
>
> That's still not to say we shouldn't do this, but I've got to say I
> think the only consumers would be old fashioned C code: the code we
> used to write before we had thread libraries that did use signals and
> poll() for a single threaded event driven monolith (think green
> threads), because all the new webby languages use threading either
> explicitly or at the core of their operation.

Regardless of how it actually might be used, I'm happy that we agree on
that this *is* the right thing to do.
Thanks,
Tadeusz