Thread (2 messages) 2 messages, 2 authors, 2011-09-23

Re: [PATCH] powerpc: Fix hugetlb with CONFIG_PPC_MM_SLICES=y

From: Becky Bruce <hidden>
Date: 2011-09-23 16:40:04

On Sep 21, 2011, at 12:58 AM, Paul Mackerras wrote:
Commit 41151e77a4 ("powerpc: Hugetlb for BookE") added some
#ifdef CONFIG_MM_SLICES conditionals to hugetlb_get_unmapped_area()
and vma_mmu_pagesize().  Unfortunately this is not the correct config
symbol; it should be CONFIG_PPC_MM_SLICES.  The result is that
attempting to use hugetlbfs on 64-bit Power server processors results
in an infinite stack recursion between get_unmapped_area() and
hugetlb_get_unmapped_area().
=20
This fixes it by changing the #ifdef to use CONFIG_PPC_MM_SLICES
in those functions and also in book3e_hugetlb_preload().
=20
Signed-off-by: Paul Mackerras <redacted>
Paul, Ben,

ACK since it looks like Ben has picked this up already..... but FYI I =
have a different version of this fix in my tree.  The =
get_unmapped_area() shouldn't be there  *at all*  - we can just use the =
generic code if we don't have slices.  So instead the whole =
hugetlb_get_unmapped_area function should be wrapped in PPC_MM_SLICES.  =
This is crufty debug stuff that I missed yanking out when I pushed the =
patch, my apologies.

I'll just submit a followup patch to fix this.

Cheers,
B
quoted hunk ↗ jump to hunk
---
arch/powerpc/mm/hugetlbpage-book3e.c |    2 +-
arch/powerpc/mm/hugetlbpage.c        |    4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
=20
diff --git a/arch/powerpc/mm/hugetlbpage-book3e.c =
b/arch/powerpc/mm/hugetlbpage-book3e.c
quoted hunk ↗ jump to hunk
index 1295b7c..343ad0b 100644
--- a/arch/powerpc/mm/hugetlbpage-book3e.c
+++ b/arch/powerpc/mm/hugetlbpage-book3e.c
@@ -52,7 +52,7 @@ void book3e_hugetlb_preload(struct mm_struct *mm, =
unsigned long ea, pte_t pte)
quoted hunk ↗ jump to hunk
	if (unlikely(is_kernel_addr(ea)))
		return;
=20
-#ifdef CONFIG_MM_SLICES
+#ifdef CONFIG_PPC_MM_SLICES
	psize =3D mmu_get_tsize(get_slice_psize(mm, ea));
	tsize =3D mmu_get_psize(psize);
	shift =3D mmu_psize_defs[psize].shift;
diff --git a/arch/powerpc/mm/hugetlbpage.c =
b/arch/powerpc/mm/hugetlbpage.c
quoted hunk ↗ jump to hunk
index 3a5f59d..48b65be 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -690,7 +690,7 @@ unsigned long hugetlb_get_unmapped_area(struct =
file *file, unsigned long addr,
					unsigned long len, unsigned long =
pgoff,
quoted hunk ↗ jump to hunk
					unsigned long flags)
{
-#ifdef CONFIG_MM_SLICES
+#ifdef CONFIG_PPC_MM_SLICES
	struct hstate *hstate =3D hstate_file(file);
	int mmu_psize =3D shift_to_mmu_psize(huge_page_shift(hstate));
=20
@@ -702,7 +702,7 @@ unsigned long hugetlb_get_unmapped_area(struct =
file *file, unsigned long addr,
=20
unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
{
-#ifdef CONFIG_MM_SLICES
+#ifdef CONFIG_PPC_MM_SLICES
	unsigned int psize =3D get_slice_psize(vma->vm_mm, =
vma->vm_start);
=20
	return 1UL << mmu_psize_to_shift(psize);
--=20
1.7.5.4
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