On Thursday 18 May 2017 02:17 PM, Michael Ellerman wrote:
"Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> writes:
On Thursday 18 May 2017 10:51 AM, Michael Ellerman wrote:
"Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxx>
---
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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