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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2013-12-20 13:35:58 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-20 12:25:45 -0800 |
| commit | 597d795a2a786d22dd872332428e2b9439ede639 (patch) | |
| tree | 1dd7be7e737649c7d346c695e0700c9732b2d681 /kernel/bounds.c | |
| parent | fff4068cba484e6b0abe334ed6b15d5a215a3b25 (diff) | |
| download | lwn-597d795a2a786d22dd872332428e2b9439ede639.tar.gz lwn-597d795a2a786d22dd872332428e2b9439ede639.zip | |
mm: do not allocate page->ptl dynamically, if spinlock_t fits to long
In struct page we have enough space to fit long-size page->ptl there,
but we use dynamically-allocated page->ptl if size(spinlock_t) is larger
than sizeof(int).
It hurts 64-bit architectures with CONFIG_GENERIC_LOCKBREAK, where
sizeof(spinlock_t) == 8, but it easily fits into struct page.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/bounds.c')
| -rw-r--r-- | kernel/bounds.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bounds.c b/kernel/bounds.c index 5253204afdca..9fd4246b04b8 100644 --- a/kernel/bounds.c +++ b/kernel/bounds.c @@ -22,6 +22,6 @@ void foo(void) #ifdef CONFIG_SMP DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS)); #endif - DEFINE(BLOATED_SPINLOCKS, sizeof(spinlock_t) > sizeof(int)); + DEFINE(SPINLOCK_SIZE, sizeof(spinlock_t)); /* End of constants */ } |