On 2016/8/19 18:25, Michal Hocko wrote:
> On Thu 18-08-16 20:05:29, Xie Yisheng wrote:
>> As we know, arm64 also support gigantic hugepage eg. 1G.
>
> Well, I do not know that. How can I check?
>
Hi Michal,
Thank you for your reply.
Maybe you can check the setup_hugepagesz()
in ./arch/arm64/hugetlbpage.c
if (ps == PMD_SIZE) {
hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
} else if (ps == PUD_SIZE) {
hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
} else if (ps == (PAGE_SIZE * CONT_PTES)) {
hugetlb_add_hstate(CONT_PTE_SHIFT);
} else if (ps == (PMD_SIZE * CONT_PMDS)) {
hugetlb_add_hstate((PMD_SHIFT + CONT_PMD_SHIFT) - PAGE_SHIFT);
} else {
hugetlb_bad_size();
pr_err("hugepagesz: Unsupported page size %lu K\n", ps >> 10);
return 0;
}
I think all of the supported hugepage size on arm64 should be listed here,
just as what X86_64 do. Therefore, I also a litter confuse about why not
enable it in hugetlb.c, though I have do some sanity test about 1G hugetlb
on arm64 and didn't find any bug.
Do I miss something?
Thanks
Xie Yisheng
> Anyway to the patch
> [...]
>> index 87e11d8..b4d8048 100644
>> --- a/mm/hugetlb.c
>> +++ b/mm/hugetlb.c
>> @@ -1022,7 +1022,8 @@ static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
>> ((node = hstate_next_node_to_free(hs, mask)) || 1); \
>> nr_nodes--)
>>
>> -#if (defined(CONFIG_X86_64) || defined(CONFIG_S390)) && \
>> +#if (defined(CONFIG_X86_64) || defined(CONFIG_S390) || \
>> + defined(CONFIG_ARM64)) && \
>> ((defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || \
>> defined(CONFIG_CMA))
>
> this ifdef is getting pretty unwieldy. For one thing I think that
> respective archs should enable ARCH_HAVE_GIGANTIC_PAGES.
I couldn't agree more about it, and will send another version, soon.
>
>> static void destroy_compound_gigantic_page(struct page *page,
>> --
>> 1.7.12.4
>>
>> --
>> To unsubscribe, send a message with 'unsubscribe linux-mm' in
>> the body to majordomo@xxxxxxxxx. For more info on Linux MM,
>> see: http://www.linux-mm.org/ .
>> Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>