Messages in this thread | | | Subject | Re: [PATCH v3 2/2] powerpc/mm/hugetlb: Add support for 1G huge pages | From | "Aneesh Kumar K.V" <> | Date | Thu, 18 May 2017 14:20:24 +0530 |
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On Thursday 18 May 2017 02:17 PM, Michael Ellerman wrote: > "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes: > >> On Thursday 18 May 2017 10:51 AM, Michael Ellerman wrote: >>> "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes: >>> >>>> POWER9 supports hugepages of size 2M and 1G in radix MMU mode. This patch >>>> enables the usage of 1G page size for hugetlbfs. This also update the helper >>>> such we can do 1G page allocation at runtime. >>>> >>>> We still don't enable 1G page size on DD1 version. This is to avoid doing >>>> workaround mentioned in commit: 6d3a0379ebdc8 (powerpc/mm: Add >>>> radix__tlb_flush_pte_p9_dd1() >>>> >>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> >>>> --- >>>> arch/powerpc/include/asm/book3s/64/hugetlb.h | 10 ++++++++++ >>>> arch/powerpc/mm/hugetlbpage.c | 7 +++++-- >>>> arch/powerpc/platforms/Kconfig.cputype | 1 + >>>> 3 files changed, 16 insertions(+), 2 deletions(-) >>> >>> I think this patch is OK, but it's very confusing because it doesn't >>> mention that it's only talking about *generic* gigantic page support. >> >> What you mean by generic gigantic page ? what is supported here is the >> gigantic page with size 1G alone ? > > What about 16G pages on pseries. > > And all the other gigantic page sizes that Book3E supports? >
None of that is supported w.r.t runtime allocation of hugepages. ie, we cannot echo nr_hugepages w.r.t them. For 16GB i am not sure it make sense, because we will rarely get such large contiguous region. W.r.t page size supported for Book3E, may be we can. But I don't have a facility to test those. Hence didn't include that.
-aneesh
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