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

From: Randy Dunlap <[email-masked]>
Date: Wed, 28 Nov 2007 17:40:14 -0800

Nish Aravamudan wrote:
> On 11/28/07, Randy Dunlap <[email-masked]> 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 <[email-masked]>
>>> ---
>>>
>>>  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 ?  :(

OK, just leave it as is, I think.

Thanks,
-- 
~Randy