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authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-16 08:22:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-16 08:22:41 -0700
commit79d8a8f736151b12129984b1250fd708440e742c (patch)
treef67eebe2bafca8820955ee9f851985a41fb32e66 /include/asm-generic
parentbd2895eeade5f11f3e5906283c630bbdb4b57454 (diff)
parentb9ec40af0e18fb7d02106be148036c2ea490fdf9 (diff)
downloadop-kernel-dev-79d8a8f736151b12129984b1250fd708440e742c.zip
op-kernel-dev-79d8a8f736151b12129984b1250fd708440e742c.tar.gz
Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu, x86: Add arch-specific this_cpu_cmpxchg_double() support percpu: Generic support for this_cpu_cmpxchg_double() alpha: use L1_CACHE_BYTES for cacheline size in the linker script percpu: align percpu readmostly subsection to cacheline Fix up trivial conflict in arch/x86/kernel/vmlinux.lds.S due to the percpu alignment having changed ("x86: Reduce back the alignment of the per-CPU data section")
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/vmlinux.lds.h35
1 files changed, 22 insertions, 13 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 906c3ce..32c45e5 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -15,7 +15,7 @@
* HEAD_TEXT_SECTION
* INIT_TEXT_SECTION(PAGE_SIZE)
* INIT_DATA_SECTION(...)
- * PERCPU(PAGE_SIZE)
+ * PERCPU(CACHELINE_SIZE, PAGE_SIZE)
* __init_end = .;
*
* _stext = .;
@@ -689,13 +689,18 @@
/**
* PERCPU_VADDR - define output section for percpu area
+ * @cacheline: cacheline size
* @vaddr: explicit base address (optional)
* @phdr: destination PHDR (optional)
*
- * Macro which expands to output section for percpu area. If @vaddr
- * is not blank, it specifies explicit base address and all percpu
- * symbols will be offset from the given address. If blank, @vaddr
- * always equals @laddr + LOAD_OFFSET.
+ * Macro which expands to output section for percpu area.
+ *
+ * @cacheline is used to align subsections to avoid false cacheline
+ * sharing between subsections for different purposes.
+ *
+ * If @vaddr is not blank, it specifies explicit base address and all
+ * percpu symbols will be offset from the given address. If blank,
+ * @vaddr always equals @laddr + LOAD_OFFSET.
*
* @phdr defines the output PHDR to use if not blank. Be warned that
* output PHDR is sticky. If @phdr is specified, the next output
@@ -706,7 +711,7 @@
* If there is no need to put the percpu section at a predetermined
* address, use PERCPU().
*/
-#define PERCPU_VADDR(vaddr, phdr) \
+#define PERCPU_VADDR(cacheline, vaddr, phdr) \
VMLINUX_SYMBOL(__per_cpu_load) = .; \
.data..percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load) \
- LOAD_OFFSET) { \
@@ -714,7 +719,9 @@
*(.data..percpu..first) \
. = ALIGN(PAGE_SIZE); \
*(.data..percpu..page_aligned) \
+ . = ALIGN(cacheline); \
*(.data..percpu..readmostly) \
+ . = ALIGN(cacheline); \
*(.data..percpu) \
*(.data..percpu..shared_aligned) \
VMLINUX_SYMBOL(__per_cpu_end) = .; \
@@ -723,18 +730,18 @@
/**
* PERCPU - define output section for percpu area, simple version
+ * @cacheline: cacheline size
* @align: required alignment
*
- * Align to @align and outputs output section for percpu area. This
- * macro doesn't maniuplate @vaddr or @phdr and __per_cpu_load and
+ * Align to @align and outputs output section for percpu area. This macro
+ * doesn't manipulate @vaddr or @phdr and __per_cpu_load and
* __per_cpu_start will be identical.
*
- * This macro is equivalent to ALIGN(align); PERCPU_VADDR( , ) except
- * that __per_cpu_load is defined as a relative symbol against
- * .data..percpu which is required for relocatable x86_32
- * configuration.
+ * This macro is equivalent to ALIGN(@align); PERCPU_VADDR(@cacheline,,)
+ * except that __per_cpu_load is defined as a relative symbol against
+ * .data..percpu which is required for relocatable x86_32 configuration.
*/
-#define PERCPU(align) \
+#define PERCPU(cacheline, align) \
. = ALIGN(align); \
.data..percpu : AT(ADDR(.data..percpu) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__per_cpu_load) = .; \
@@ -742,7 +749,9 @@
*(.data..percpu..first) \
. = ALIGN(PAGE_SIZE); \
*(.data..percpu..page_aligned) \
+ . = ALIGN(cacheline); \
*(.data..percpu..readmostly) \
+ . = ALIGN(cacheline); \
*(.data..percpu) \
*(.data..percpu..shared_aligned) \
VMLINUX_SYMBOL(__per_cpu_end) = .; \
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