Re: [Qemu-devel] [PATCH 1/2] trace: Add simple tracing support

[Christoph Hellwig]

On Fri, May 21, 2010 at 09:49:56PM +0100, Stefan Hajnoczi wrote:
> http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps
> 
> Requires kernel support - not sure if enough of utrace is in mainline
> for this to work out-of-the-box across distros.

Nothing of utrace is in mainline, nevermind the whole systemtap code
which is intentionally keep out of the kernel tree.  Using this means
that for every probe in userspace code you need to keep the configured
source tree of the currently running kernel around, which is completely
unusable for typical developer setups.