Re: [PATCH 6/6] psi: introduce psi monitor

Peter Zijlstra
2018-12-18T11:20:56Z

On Tue, Dec 18, 2018 at 11:46:22AM +0100, Peter Zijlstra wrote:
> On Mon, Dec 17, 2018 at 05:21:05PM -0800, Suren Baghdasaryan wrote:
> > On Mon, Dec 17, 2018 at 8:22 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> > > How well has this thing been fuzzed? Custom string parser, yay!
> >
> > Honestly, not much. Normal cases and some obvious corner cases. Will
> > check if I can use some fuzzer to get more coverage or will write a
> > script.
> > I'm not thrilled about writing a custom parser, so if there is a
> > better way to handle this please advise.
>
> The grammar seems fairly simple, something like:
>
> some-full = "some" | "full" ;
> threshold-abs = integer ;
> threshold-pct = integer, { "%" } ;

Sorry, no {} there obviously. That '%' isn't optional.

> threshold = threshold-abs | threshold-pct ;
> window = integer ;
> trigger = some-full, space, threshold, space, window ;

Clearly it's been a fair while since I wrote BNF like stuff ;-)