Re: [PATCH 1/4] mm/hugetlb: Enable PUD level huge page migration

[Suzuki K Poulose]

On 03/10/18 12:10, Anshuman Khandual wrote:
> On 10/03/2018 03:52 PM, Suzuki K Poulose wrote:
> > On 02/10/18 13:56, Anshuman Khandual wrote:
> > > On 10/02/2018 06:08 PM, Suzuki K Poulose wrote:
> > > > Hi Anshuman
> > > >
> > > > On 02/10/18 13:15, Anshuman Khandual wrote:
> > > > > Architectures like arm64 have PUD level HugeTLB pages for certain configs
> > > > > (1GB huge page is PUD based on ARM64_4K_PAGES base page size) that can be
> > > > > enabled for migration. It can be achieved through checking for PUD_SHIFT
> > > > > order based HugeTLB pages during migration.
> > > > >
> > > > > Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> > > > > ---
> > > > >  ÂÂ include/linux/hugetlb.h | 3 ++-
> > > > >  ÂÂ 1 file changed, 2 insertions(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> > > > > index 6b68e34..9c1b77f 100644
> > > > > --- a/include/linux/hugetlb.h
> > > > > +++ b/include/linux/hugetlb.h
> > > > > @@ -483,7 +483,8 @@ static inline bool hugepage_migration_supported(struct hstate *h)
> > > > >  ÂÂ {
> > > > >  ÂÂ #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
> > > > >  ÂÂÂÂÂÂ if ((huge_page_shift(h) == PMD_SHIFT) ||
> > > > > -ÂÂÂÂÂÂÂ (huge_page_shift(h) == PGDIR_SHIFT))
> > > > > +ÂÂÂÂÂÂÂ (huge_page_shift(h) == PUD_SHIFT) ||
> > > >
> > > >
> > > > > +ÂÂÂÂÂÂÂÂÂÂÂ (huge_page_shift(h) == PGDIR_SHIFT))
> > > >
> > > > nit: Extra Tab ^^.
> > >
> > > The tab is in there when you apply this patch and all three checks are tab separated
> > > in a newline.
> >
> > Well, with the patch applied, at least I can see 2 tabs for the
> > PUD_SHIFT check and 3 tabs for PGDIR_SHIFT check. Which seems
> > inconsistent. Is it just me (my mail client) ?
>
> I am sorry, you are right. Did not understand your point earlier. Yeah there is
> increasing number of tabs for each new line with a conditional check. Is there
> a problem with this style of indentation ? Though I will be happy to change.

I have been under the idea that all the checks at the same level could
have the same indentation. (i.e, 2 tabs in this case for each). Looks
like there is no rule about it. How about replacing it with a
switch..case  ?

Cheers
Suzuki