Re: [PATCH v2] perf tools: allow map files to specify DSO

[Josh Hunt]

On 05/07/2018 11:40 AM, Andi Kleen wrote:
> On Mon, May 07, 2018 at 02:24:16PM -0400, Josh Hunt wrote:
> > Add the ability to specify a DSO in the /tmp/perf-<PID>.map file.
> > The DSO should be the first line in the file and readable by the
> > running user. If a valid DSO is found all other contents of the
> > file will be ignored. This allows things like callchain unwinding
> > with DWARF to work.
>
> FWIW it's ok, but also obsolete with Kirill's large-pages-in-tmpfs
> work in newer kernels. With that you can just copy the executable into
> a 2MB tmpfs and disable the manual huge page copying and everything
> should work as usually.
>
> So essentially it's only a hack for old kernels and old binaries.
>
> But doesn't hurt I guess.

Ah, very interesting. I wasn't aware of this. Can you point me to some 
more details on this process?

Thanks
Josh