We use the default hugetlb page size to calculate pageblock order.
set_pageblock_order happens early in the boot and we need to make sure
we set the default hugetlb page size before that to compute the right
pageblock_order value.
arch_initcalls get called later in the boot as shown below
[c000000007383b10] [c000000001289328] hugetlbpage_init+0x2b8/0x2f8
[c000000007383bc0] [c0000000012749e4] do_one_initcall+0x14c/0x320
[c000000007383c90] [c00000000127505c] kernel_init_freeable+0x410/0x4e8
[c000000007383da0] [c000000000012664] kernel_init+0x30/0x15c
[c000000007383e10] [c00000000000cf14] ret_from_kernel_thread+0x5c/0x64
and we do the pageblock_order initialization early during the boot.
[c0000000018bfc80] [c0000000012ae120] set_pageblock_order+0x50/0x64
[c0000000018bfca0] [c0000000012b3d94] sparse_init+0x188/0x268
[c0000000018bfd60] [c000000001288bfc] initmem_init+0x28c/0x328
[c0000000018bfe50] [c00000000127b370] setup_arch+0x410/0x480
[c0000000018bfed0] [c00000000127401c] start_kernel+0xb8/0x934
[c0000000018bff90] [c00000000000d984] start_here_common+0x1c/0x98
IIUC we always had this issue. But it was not a problem for hash because
MAX_ORDER - 1 was the same as HUGETLB_PAGE_ORDER (8) in the case of hash (16MB).
With radix, HUGETLB_PAGE_ORDER will be 5 (2M size) and hence we would
want pageblock_order to be 5 instead of 8.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
arch/powerpc/include/asm/hugetlb.h | 5 ++++-
arch/powerpc/mm/book3s64/hugetlbpage.c | 2 +-
arch/powerpc/mm/hugetlbpage.c | 5 +----
arch/powerpc/mm/init_64.c | 4 ++++
4 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index 962708fa1017..6a1a1ac5743b 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -15,7 +15,7 @@
extern bool hugetlb_disabled;
-void __init hugetlbpage_init_default(void);
+void __init hugetlbpage_init_defaultsize(void);
int slice_is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
unsigned long len);
@@ -76,6 +76,9 @@ static inline void __init gigantic_hugetlb_cma_reserve(void)
{
}
+static inline void __init hugetlbpage_init_defaultsize(void)
+{
+}
#endif /* CONFIG_HUGETLB_PAGE */
#endif /* _ASM_POWERPC_HUGETLB_H */
diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c b/arch/powerpc/mm/book3s64/hugetlbpage.c
index ea8f83afb0ae..3bc0eb21b2a0 100644
--- a/arch/powerpc/mm/book3s64/hugetlbpage.c
+++ b/arch/powerpc/mm/book3s64/hugetlbpage.c
@@ -150,7 +150,7 @@ void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr
set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
}
-void __init hugetlbpage_init_default(void)
+void __init hugetlbpage_init_defaultsize(void)
{
/* Set default large page size. Currently, we pick 16M or 1M
* depending on what is available
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index ddead41e2194..b642a5a8668f 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -664,10 +664,7 @@ static int __init hugetlbpage_init(void)
configured = true;
}
- if (configured) {
- if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
- hugetlbpage_init_default();
- } else
+ if (!configured)
pr_info("Failed to initialize. Disabling HugeTLB");
return 0;
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index 35f46bf54281..83c0ee9fbf05 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -59,6 +59,7 @@
#include <asm/sections.h>
#include <asm/iommu.h>
#include <asm/vdso.h>
+#include <asm/hugetlb.h>
#include <mm/mmu_decl.h>
@@ -513,6 +514,9 @@ void __init mmu_early_init_devtree(void)
} else
hash__early_init_devtree();
+ if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
+ hugetlbpage_init_defaultsize();
+
if (!(cur_cpu_spec->mmu_features & MMU_FTR_HPTE_TABLE) &&
!(cur_cpu_spec->mmu_features & MMU_FTR_TYPE_RADIX))
panic("kernel does not support any MMU type offered by platform");
--
2.34.1
