[PATCH] nvme: trace: parse format nvm command in detail

[Keith Busch]

On Mon, Jan 11, 2021 at 09:10:34AM -0800, Dan Williams wrote:
> On Mon, Jan 11, 2021 at 9:01 AM Keith Busch <kbusch at kernel.org> wrote:
> >
> > On Fri, Jan 08, 2021 at 04:12:31PM -0800, Dan Williams wrote:
> > > Is there a more centralized place to land such a helper? trace-cmd,
> > > perf? The nice thing about kernel parsing is I don't need to have a
> > > separate pile of disparate tools across subsystems.
> >
> > Yes, I just placed it in a temporary location to see if the other nvme
> > stakeholders are okay with the idea. If so, I can make a real patch
> > series to remove the in-kernel decoding, and add the parsing script
> > somewhere in tools/.
> 
> "Somewhere in tools/" is still not quite what I'm asking for, I want
> something nearly as automatic and seamless as the kernel ftrace pipe.
> If I need nvme tools for nvme events and mce tools for mce events etc,
> I'd rather just have decode in the kernel. Perhaps this is a use case
> for a usermode helper that accompanies a new kernel tracing file?. If
> the helper exists the events supported events are decoded if the
> helper is missing the interface is equivalent to the raw formatted
> events. Decoded events "just work".

My only concern is that decoding omits fields, so you have to ugprade
your kernel in order to see the missing ones when the current kernel's
decoding doesn't "just work". If that's how people want to maintain
them, then I won't object any longer.