Re: [RFC PATCH 0/2] improve vmalloc allocation

Michal Hocko
2018-10-23T07:23:10Z

Hi Shuah,

On Mon 22-10-18 18:52:53, Uladzislau Rezki wrote:
> On Mon, Oct 22, 2018 at 02:51:42PM +0200, Michal Hocko wrote:
> > Hi,
> > I haven't read through the implementation yet but I have say that I
> > really love this cover letter. It is clear on intetion, it covers design
> > from high level enough to start discussion and provides a very nice
> > testing coverage. Nice work!
> >
> > I also think that we need a better performing vmalloc implementation
> > long term because of the increasing number of kvmalloc users.
> >
> > I just have two mostly workflow specific comments.
> >
> > > A test-suite patch you can find here, it is based on 4.18 kernel.
> > > ftp://vps418301.ovh.net/incoming/0001-mm-vmalloc-stress-test-suite-v4.18.patch
> >
> > Can you fit this stress test into the standard self test machinery?
> >
> If you mean "tools/testing/selftests", then i can fit that as a kernel module.
> But not all the tests i can trigger from kernel module, because 3 of 8 tests
> use __vmalloc_node_range() function that is not marked as EXPORT_SYMBOL.

Is there any way to conditionally export these internal symbols just for
kselftests? Or is there any other standard way how to test internal
functionality that is not exported to modules?
--
Michal Hocko
SUSE Labs