Re: [PATCH 2/2] /proc/stat: Add sysctl parameter to control irq counts latency

From: Alexey Dobriyan
Date: Mon Jan 07 2019 - 11:33:09 EST


On Mon, Jan 07, 2019 at 07:58:40AM -0800, Matthew Wilcox wrote:
> On Mon, Jan 07, 2019 at 10:12:58AM -0500, Waiman Long wrote:

> > A new "fs/proc-stat-irqs-latency-ms" sysctl parameter is now added to
>
> No. No, no, no, no, no. No.
>
> Stop adding new sysctls for this kind of thing. It's just a way to shift
> blame from us (who allegedly know what we're doing) to the sysadmin
> (who probably has better things to be doing than keeping up with the
> intricacies of development of every single piece of software running on
> their system).
>
> Let's figure out what this _should_ be.

Yeah, let's start interrogating about which values specifically this
super sekret applications wants.

I assume CPU stats, so system call which returns CPU statistics in binary form.

> Why are you caching the _output_ of calling sprintf(), rather than caching the
> values of each interrupt?

For output caching string is better, but I'm not defending the patch.