diff options
| author | Hugh Dickins <hughd@google.com> | 2016-05-19 17:13:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-19 19:12:14 -0700 |
| commit | fd8cfd3000191cb7f5b9ea8640bd46181f6b4b74 (patch) | |
| tree | 86c96294eb99388fa70ea420019d2a9e365cf4ca /include/asm-generic/pgtable.h | |
| parent | 1d069b7dd56728a0eb6acb138dce0d37600dee00 (diff) | |
| download | lwn-fd8cfd3000191cb7f5b9ea8640bd46181f6b4b74.tar.gz lwn-fd8cfd3000191cb7f5b9ea8640bd46181f6b4b74.zip | |
arch: fix has_transparent_hugepage()
I've just discovered that the useful-sounding has_transparent_hugepage()
is actually an architecture-dependent minefield: on some arches it only
builds if CONFIG_TRANSPARENT_HUGEPAGE=y, on others it's also there when
not, but on some of those (arm and arm64) it then gives the wrong
answer; and on mips alone it's marked __init, which would crash if
called later (but so far it has not been called later).
Straighten this out: make it available to all configs, with a sensible
default in asm-generic/pgtable.h, removing its definitions from those
arches (arc, arm, arm64, sparc, tile) which are served by the default,
adding #define has_transparent_hugepage has_transparent_hugepage to
those (mips, powerpc, s390, x86) which need to override the default at
runtime, and removing the __init from mips (but maybe that kind of code
should be avoided after init: set a static variable the first time it's
called).
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Ning Qu <quning@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc]
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [arch/s390]
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-generic/pgtable.h')
| -rw-r--r-- | include/asm-generic/pgtable.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 9401f4819891..d4458b6dbfb4 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -806,4 +806,12 @@ static inline int pmd_clear_huge(pmd_t *pmd) #define io_remap_pfn_range remap_pfn_range #endif +#ifndef has_transparent_hugepage +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#define has_transparent_hugepage() 1 +#else +#define has_transparent_hugepage() 0 +#endif +#endif + #endif /* _ASM_GENERIC_PGTABLE_H */ |