Michael Ellerman <m...@ellerman.id.au> writes:
On Fri, 2016-19-02 at 05:38:47 UTC, Rashmica Gupta wrote:
Currently on PPC64 changing kernel pagesize from 4K to 64K leaves
FORCE_MAX_ZONEORDER set to 13 - which produces a compile error.
...
So, update the range of FORCE_MAX_ZONEORDER from 9-64 to 8-9 for 64K pages
and from 13-64 to 9-13 for 4K pages.
Signed-off-by: Rashmica Gupta <rashm...@gmail.com>
Reviewed-by: Balbir Singh <bsinghar...@gmail.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/a7ee539584acf4a565b7439cea
HPAGE_PMD_ORDER is not something we should check w.r.t 4k linux page
size. We do have the below constraint w.r.t hugetlb pages
static inline bool hstate_is_gigantic(struct hstate *h)
{
return huge_page_order(h) >= MAX_ORDER;
}
That require MAX_ORDER to be greater than 12.
Did we test hugetlbfs 4k config with this patch ? Will it work if we
start marking hugepage as gigantic page ?
-aneesh
Hello Rashmica,
With upstream linux kernel 4.8.0-rc1-00006-gbae9cc6 compiled with linux
4k page size we are not able set hugepages, Aneesh had a look at the
problem and he mentioned this commit is causing the issue.
*Details:*
We are using pkvm ubuntu 16.04 guest with upstream kernel
[4.8.0-rc1-00006-gbae9cc6] compiled with 4k page size
o/p from guest:
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 16384 kB
Page sizes from device-tree: [dmesg]
[ 0.000000] base_shift=12: shift=12, sllp=0x0000, avpnm=0x00000000,
tlbiel=1, penc=0
[ 0.000000] base_shift=12: shift=24, sllp=0x0000, avpnm=0x00000000,
tlbiel=1, penc=56
[ 0.000000] base_shift=24: shift=24, sllp=0x0100, avpnm=0x00000001,
tlbiel=0, penc=0
while trying to configure the hugepages inside the guest it throws the
below error:
echo 100 > /proc/sys/vm/nr_hugepages
-bash: echo: write error: Invalid argument
*Note*: we do not see the problem when the linux page is 64k
Thanks,
Santhosh G
