Re: [PATCH 0/2]: Add sparc64 ftrace support.

[Steven Rostedt <srostedt@redhat.com>]

David Miller wrote:
> This was a lot more trivial than I expected, about a 20 minute
> hack.  Most of the time was spent on test boots :)

Cool! This is what we tried to do with ftrace (make it trivial ;-)

> 
> The first patch removes the packed attribute from the ftrace_page
> blob of dynamic ftrace entries, because not only does it cause
> unaligned accesses on sparc64 it's also totally useless.
> 
> The second patch adds sparc64 ftrace support.
> 
> One thing I noticed is that sparc64 uses an mcount implementation
> already for a quick-and-dirty stack usage checker.  I tried to
> make them live alongside eachother.
> 
> Next, I think the mcount symbol export needs some tweaking.  On sparc,
> the symbol _mcount is what the compiler references (this seems to be a
> sparc sysv4'ism) whereas on x86 it appears that plain "mcount" is
> used.  I provide both symbols and we already have a local export of
> "_mcount" to take care of this.  I think architectures should deal
> with this symbol exporting since it is different on every system.

No, the same is for PPC (_mcount). I have a port for this ready. I'll 
look at your code and compare it with my PPC port.

Ingo, do you think it's time I can hand the PPC stuff over to you? I'll 
just have to update it to the lastest linux-ftrace.git.

Thanks,

-- Steve