Re: runsvdir polling

From: <39066dd5_at_gmail.com>
Date: Sun, 15 Jan 2017 14:12:32 -0800

On Sun, Jan 15, 2017 at 11:38:21AM +0000, Laurent Bercot wrote:
> Polling is evil for several reasons, the two most important of them being
> the following.

Harsh but true.

> I have met a real-life example of this at Google, of all places: sending
...
> I have also met a real-life example of this, when I was working at
> Sagemcom (a French manufacturer of embedded devices), making the base
> system for an energy gateway (the thing that's supposed to collect and

Thanks for sharing those, I find the Google example surprising given their reputation but once you've built surch a large infrastructure I suppose making changes becomes very hard.

> When you're an init system, i.e. the lowest possible level for user-space
> software, and you *already* introduce polling, well, it doesn't bode well
> for the rest of your software stack. Your energy-saving device is already
> screwed, and automation that relies on runsvdir picking up a new service
> is already eating an average 7 second delay. As a desktop user, you
> obviously don't care; as a software architect, this makes me shake my head.
> Even systemd does better on that point.

That is the crux of my original motivation, I don't actually know if the power consumption is going to be an issue but when I see CPU time accumulating for a process that should be idle then it's a cause for suspicion. The tradeoff here favors patching it if it's really an intrinsic problem and not some kind of misconfiguration.
Received on Sun Jan 15 2017 - 22:12:32 UTC