Re: [PATCH RESEND 0/8] Fix mmap base in bottom-up mmap

[Alex Ghiti]

On 8/26/19 6:37 PM, Helge Deller wrote:
> On 26.08.19 09:34, Alexandre Ghiti wrote:
> > On 6/20/19 7:03 AM, Alexandre Ghiti wrote:
> > > This series fixes the fallback of the top-down mmap: in case of
> > > failure, a bottom-up scheme can be tried as a last resort between
> > > the top-down mmap base and the stack, hoping for a large unused stack
> > > limit.
> > >
> > > Lots of architectures and even mm code start this fallback
> > > at TASK_UNMAPPED_BASE, which is useless since the top-down scheme
> > > already failed on the whole address space: instead, simply use
> > > mmap_base.
> > >
> > > Along the way, it allows to get rid of of mmap_legacy_base and
> > > mmap_compat_legacy_base from mm_struct.
> > >
> > > Note that arm and mips already implement this behaviour.
> > >
> > > Alexandre Ghiti (8):
> > > ÂÂ s390: Start fallback of top-down mmap at mm->mmap_base
> > > ÂÂ sh: Start fallback of top-down mmap at mm->mmap_base
> > > ÂÂ sparc: Start fallback of top-down mmap at mm->mmap_base
> > > ÂÂ x86, hugetlbpage: Start fallback of top-down mmap at mm->mmap_base
> > > ÂÂ mm: Start fallback top-down mmap at mm->mmap_base
> > > ÂÂ parisc: Use mmap_base, not mmap_legacy_base, as low_limit for
> > > ÂÂÂÂ bottom-up mmap
> > > ÂÂ x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for 
> > > bottom-up
> > > ÂÂÂÂ mmap
> > > ÂÂ mm: Remove mmap_legacy_base and mmap_compat_legacy_code fields from
> > > ÂÂÂÂ mm_struct
> > >
> > >  arch/parisc/kernel/sys_parisc.c | 8 +++-----
> > > Â arch/s390/mm/mmap.cÂÂÂÂÂÂÂÂÂÂÂÂÂ |Â 2 +-
> > > Â arch/sh/mm/mmap.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |Â 2 +-
> > > Â arch/sparc/kernel/sys_sparc_64.c |Â 2 +-
> > > Â arch/sparc/mm/hugetlbpage.cÂÂÂÂÂ |Â 2 +-
> > > Â arch/x86/include/asm/elf.hÂÂÂÂÂÂ |Â 2 +-
> > > Â arch/x86/kernel/sys_x86_64.cÂÂÂÂ |Â 4 ++--
> > > Â arch/x86/mm/hugetlbpage.cÂÂÂÂÂÂÂ |Â 7 ++++---
> > > Â arch/x86/mm/mmap.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂ | 20 +++++++++-----------
> > > Â include/linux/mm_types.hÂÂÂÂÂÂÂÂ |Â 2 --
> > > Â mm/debug.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |Â 4 ++--
> > > Â mm/mmap.cÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ |Â 2 +-
> > > Â 12 files changed, 26 insertions(+), 31 deletions(-)
> >
> > Any thoughts about that series ? As said before, this is just a 
> > preparatory patchset in order to
> > merge x86 mmap top down code with the generic version.
>
> I just tested your patch series successfully on the parisc
> architeture. You may add:
>
> Tested-by: Helge Deller <deller@xxxxxx> # parisc

Thanks again Helge !

Alex


> Thanks!
> Helge