Re: kvmmmu tracing

Avi Kivity
2009-11-24T10:34:29Z

On 11/24/2009 12:05 PM, Johannes Berg wrote:
> On Tue, 2009-11-24 at 11:50 +0200, Avi Kivity wrote:
>
>> 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?
>>
> It's a big C expression that trace-cmd can't parse :)
>

Um, C can be easily parsed with a C compiler. I don't think you can
expect it to be a plain format string and argument list.

>> Is userspace reading mmutrace.h? When the structure attributes can be
>> exported via /sys/kernel/debug/tracing?
>>
> Yes ... look
> at /sys/kernel/debug/tracing/events/kvmmmu/kvm_mmu_unsync_page/format
> for instance.
>

You can fall back to using the attributes to build your own format string.

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