[LTP] [PATCH] mtest06/mmap1: Further limit distant mmap size

[Jan Stancek]

On Thu, May 20, 2021 at 1:43 PM Cyril Hrubis <chrubis@suse.cz> wrote:
>
> Hi!
> > > Though on recent kernels (starting with 5.2, commit
> > > 8c7829b04c523cdc732cb77f59f03320e09f3386 ("mm: fix false-positive
> > > OVERCOMMIT_GUESS failures"), overcommit accounting allows for allocating up
> > > to MemTotal memory, older kernels have a much more complicated overcommit
> > > guess accounting.
> > >
> > > That leads to mmap failing on small enough systems:
> > >
> > > mmap1.c:205: TBROK: mmap((nil),2088370176,3,34,-1,0) failed: ENOMEM (12)
> > >
> > > Allocating only half of the total memory would generally work on test
> > > systems.
> > >
> > > Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
> >
> > Thanks for patch.
> >
> > Acked-by: Jan Stancek <jstancek@redhat.com>
>
> Looks safe enough for the release, as far as I can tell the test
> shouldn't care at all where we map the block of memory.
>
> Jan looks like you originaly wrote the test, do you agree that this
> should go in now?

That's fine by me. As you said, the change in size doesn't matter that
much for the test.

>
> --
> Cyril Hrubis
> chrubis@suse.cz
>