Re: kvmmmu tracing

Avi Kivity
2009-11-24T09:51:28Z

On 11/23/2009 01:06 PM, Johannes Berg wrote:
> Commit f691fe1da7e2715137d21ae5a80bec64db4625db is really broken wrt.
> the userspace interface for tracing because of the weird
> KVM_MMU_PAGE_PRINTK macro.
>
>

Can you explain what is wrong with it?

> Maybe we should have a "unsafe for export" flag for events, if they do
> strange things like that?
>
> As it stands, I can't use trace-cmd on an x86 machine that has kvm
> enabled because it will try to read all the kvm stuff. Arguably, it
> should only try to parse it when it needs it (i.e. not for me) but still
> it's very inconvenient to export something to userspace that it cannot
> possibly understand.
>

Is userspace reading mmutrace.h? When the structure attributes can be
exported via /sys/kernel/debug/tracing?

--
error compiling committee.c: too many arguments to function