Comments on: Direct input support for polling

By: mer

mer — Thu, 05 Oct 2017 21:44:58 +0000

Sometimes it just means you haven’t thought of all the ways it could be run. “should never be possible” is not “impossible”. multiple cores, multiple cpus, faster cpus, sometimes what should never be possible happens.

By: Anonymous

Anonymous — Thu, 05 Oct 2017 18:33:25 +0000

@flavio

i agree. definitely seems odd to include code in your codebase that should never be possible to run.

By: Flavio

Flavio — Thu, 05 Oct 2017 18:10:17 +0000

How common is it to write code for “situation [that] should not be possible to even get into”, like the commit message states below:

http://lists.dragonflybsd.org/pipermail/commits/2017-September/626484.html

By: mer

mer — Thu, 05 Oct 2017 10:41:27 +0000

Anonymous, you left out a very important piece of the commit message:
“…in critical section”
Full commit message is:
git: polling: Don’t do direct input in critical section.

Which is drastically different than:
Don’t do direct input.

Although a quick look at the patch referenced in your link, I think Sepherosa added to the polling so that higher priority interrupt sources don’t get starved.

By: Anonymous

Anonymous — Wed, 04 Oct 2017 21:56:39 +0000

I’m confused because this commit message below, Sepherosa says to NOT use direct input.

http://lists.dragonflybsd.org/pipermail/commits/2017-September/626407.html