Re: [PATCH 9/18] 2.6.17.9 perfmon2 patch for review: kernel-level interface

[Chuck Ebbert <76306.1226@compuserve.com>]

On Wed, 23 Aug 2006 15:54:47 -0700, Andrew Morton wrote:

> > > Some users have requested the ability to create a monitoring session
> > > with perfmon2 from iside the kernel using a kernel thread. Perfmon2
> > > leverages a lot of kernel mechanisms which are not easy to use for
> > > inside the kernel: e.g. file descriptor, signals, system calls.
> > 
> > Again, please drop this.  There are no planned intree kernel users
> > so far, and once we add them we can architect a proper API for them.
> > Getting rid of this should also help to collapse the tons of useless
> > abstractions layers in the current perfmon code.
> > 
> 
> Yes, I think we either need a stronger argument for including this code, or
> we drop it.

This interface is for people writing kprobes who want to do performance
monitoring within their probe code.  There will probably never be any
in-kernel users, just like there are no in-kernel users of kprobes.

> It is especially worrisome that the exports which are added here are plain
> old EXPORT_SYMBOL().

kprobes exports are all GPL, so these should be too.

-- 
Chuck