On 11/16/2011 03:18 PM, David Rientjes wrote:
On Wed, 16 Nov 2011, David Daney wrote:
This is required now to get MIPS kernels to compile with
I should have been more specific. The failure is in Ralf's
I can't find that branch (it's not in Ralf's tree at git.kernel.org), so
I'm looking at next-20111116. It doesn't compile for mips for other
reasons related to arch/mips/sgi-ip22/ip22-gio.c.
Ralf's various trees are accessible via linux-mips.org
This is definitely the wrong fix, anyway, and it would require a change to
arch/mips/include/asm/page.h instead since it's localized to mips,
No, all we are doing is supplying a dummy definition for HPAGE_SHIFT as we
currently have for HPAGE_SIZE and HPAGE_MASK.
Which is wrong. MIPS code should not be using HPAGE_SHIFT without
CONFIG_HUGETLB_PAGE and in fact defines it itself for such a configuration
in arch/mips/include/asm/page.h. The only generic uses are in
page_alloc.c where we need CONFIG_HUGETLB_PAGE_SIZE_VARIABLE, which isn't
available on mips, and in mm/hugetlb.c which requires CONFIG_HUGETLB_PAGE
by way of CONFIG_HUGETLBFS.
So feel free to show the actual compile error this time and I'll suggest a
mips fix for it.
arch/mips/mm/tlb-r4k.c: In function ‘local_flush_tlb_range’:
arch/mips/mm/tlb-r4k.c:129:28: error: ‘HPAGE_SHIFT’ undeclared (first
use in this function)
However, I call B.S. on your reasoning.
It is a well established kernel idiom to supply dummy values for symbols
that are required to be defined in order to form a syntactically correct
C program, but that are known by the programmer to be used only on dead
This is exactly what we are doing here.
To do otherwise requires that code be cluttered with #ifdefery.
Signed-off-by: David Daney<email@example.com>
include/linux/hugetlb.h | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 19644e0..746d543 100644
@@ -113,6 +113,7 @@ static inline void copy_huge_page(struct page *dst,
struct page *src)
#define HPAGE_MASK PAGE_MASK /* Keep the compiler
#define HPAGE_SIZE PAGE_SIZE
Why didn't you NACK the addition of these two lines too?
Following your logic, we should remove these and patch up all the architecture
specific files instead.
I think it's a worthwhile goal to remove these as well, yes.