[PATCH 1/2] powerpc: add hugepagesz boot-time parameter

[Nish Aravamudan]

On 11/28/07, Randy Dunlap <randy.dunlap at oracle.com> wrote:
> Nish Aravamudan wrote:
> > On 11/28/07, Randy Dunlap <randy.dunlap at oracle.com> wrote:
> >> On Tue, 27 Nov 2007 23:03:10 -0600 Jon Tollefson wrote:
> >>
> >>> This patch adds the hugepagesz boot-time parameter for ppc64 that lets
> >>> you pick the size for your huge pages.  The choices available are 64K
> >>> and 16M.  It defaults to 16M (previously the only choice) if nothing or
> >>> an invalid choice is specified.  Tested 64K huge pages with the
> >>> libhugetlbfs 1.2 release with its 'make func' and 'make stress' test
> >>> invocations.
> >>>
> >>> This patch requires the patch posted by Mel Gorman that adds
> >>> HUGETLB_PAGE_SIZE_VARIABLE; "[PATCH] Fix boot problem with iSeries
> >>> lacking hugepage support" on 2007-11-15.
> >>>
> >>> Signed-off-by: Jon Tollefson <kniht at linux.vnet.ibm.com>
> >>> ---
> >>>
> >>>  Documentation/kernel-parameters.txt |    1
> >>>  arch/powerpc/mm/hash_utils_64.c     |   11 +--------
> >>>  arch/powerpc/mm/hugetlbpage.c       |   41 ++++++++++++++++++++++++++++++++++++
> >>>  include/asm-powerpc/mmu-hash64.h    |    1
> >>>  mm/hugetlb.c                        |    1
> >>>  5 files changed, 46 insertions(+), 9 deletions(-)
> >>>
> >>> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> >>> index 33121d6..2fc1fb8 100644
> >>> --- a/Documentation/kernel-parameters.txt
> >>> +++ b/Documentation/kernel-parameters.txt
> >>> @@ -685,6 +685,7 @@ and is between 256 and 4096 characters. It is defined in the file
> >>>                       See Documentation/isdn/README.HiSax.
> >>>
> >>>       hugepages=      [HW,X86-32,IA-64] Maximal number of HugeTLB pages.
> >>> +     hugepagesz=     [HW,IA-64,PPC] The size of the HugeTLB pages.
> >> Any chance of spelling it as "hugepagesize" so that it's a little
> >> less cryptic and more difficult to typo as "hugepages"?
> >> (i.e., less confusion between them)
> >
> > It already exists as hugepagesz= for IA64. Changing it to hugepagesize
> > would either make ppc be different than IA64, or require keeping both
> > so as to make IA64 setups continue working as before?
>
> Oh, but it wasn't in Doc/kernel-parameters.txt ?  :(

Nope :( I wonder how many other kernel parameters are in the same
boat? Where's an RPJDay-script when you need it?

> OK, just leave it as is, I think.

Yeah, I guess that's probably easiest...unfortunately.

-Nish