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

[Andi Kleen]

On Mon, May 07, 2018 at 02:30:32PM -0700, Josh Hunt wrote:
> 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?

See commit 5a6e75f8110c97e2a5488894d4e922187e6cb343

-Andi