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Message-Id: <20081117132631.76367DDE07@ozlabs.org>
Date: Mon Nov 17 23:48:27 CST 2008
From: Rusty Russell <rusty@...tcorp.com.au>
To: linux-kernel@...r.kernel.org
Cc: Christoph Lameter <cl@...ux-foundation.org>
Subject: [PATCH 6/7] Improve alloc_percpu: __get_cpu_ptr/get_cpu_ptr/put_cpu_ptr
Now we have a decent implementation it makes sense to have an
interface for "this cpu", analogous to __get_cpu_var.
Alpha is untested.
Signed-off-by: Rusty Russell <rusty@...tcorp.com.au>
Cc: Christoph Lameter <cl@...ux-foundation.org>
---
arch/alpha/include/asm/percpu.h | 10 ++++++++++
include/asm-generic/percpu.h | 11 +++++++++++
include/linux/percpu.h | 16 ++++++++++++++++
3 files changed, 37 insertions(+)
diff -r 0fb05e4271a6 arch/alpha/include/asm/percpu.h
--- a/arch/alpha/include/asm/percpu.h Mon Nov 17 22:19:40 2008 +1030
+++ b/arch/alpha/include/asm/percpu.h Mon Nov 17 22:21:09 2008 +1030
@@ -62,8 +62,16 @@
(*SHIFT_PERCPU_PTR(var, my_cpu_offset))
#define __raw_get_cpu_var(var) \
(*SHIFT_PERCPU_PTR(var, __my_cpu_offset))
+#define __get_cpu_ptr(ptr) \
+ RELOC_HIDE(ptr, my_cpu_offset)
+#define __raw_get_cpu_ptr(ptr) \
+ RELOC_HIDE(ptr, __my_cpu_offset)
#define per_cpu_ptr(ptr, cpu) \
RELOC_HIDE((ptr), (per_cpu_offset(cpu)))
+#define __get_cpu_ptr(ptr) \
+ RELOC_HIDE(ptr, my_cpu_offset)
+#define __raw_get_cpu_ptr(ptr) \
+ RELOC_HIDE(ptr, __my_cpu_offset)
#else /* ! SMP */
@@ -71,6 +79,8 @@
#define __get_cpu_var(var) per_cpu_var(var)
#define __raw_get_cpu_var(var) per_cpu_var(var)
#define per_cpu_ptr(ptr, cpu) (ptr)
+#define __get_cpu_ptr(ptr) (ptr)
+#define __raw_get_cpu_ptr(ptr) (ptr)
#define PER_CPU_ATTRIBUTES
diff -r 0fb05e4271a6 include/asm-generic/percpu.h
--- a/include/asm-generic/percpu.h Mon Nov 17 22:19:40 2008 +1030
+++ b/include/asm-generic/percpu.h Mon Nov 17 22:21:09 2008 +1030
@@ -72,6 +72,15 @@
#define per_cpu_ptr(ptr, cpu) \
RELOC_HIDE((ptr), (per_cpu_offset(cpu)))
+/**
+ * __get_cpu_ptr - get a pointer to this cpu's allocated memory
+ * @ptr: the pointer returned from alloc_percpu
+ *
+ * Similar to __get_cpu_var(), except for dynamic memory.
+ */
+#define __get_cpu_ptr(ptr) RELOC_HIDE(ptr, my_cpu_offset)
+#define __raw_get_cpu_ptr(ptr) RELOC_HIDE(ptr, __my_cpu_offset)
+
#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
extern void setup_per_cpu_areas(void);
#endif
@@ -82,6 +91,8 @@
#define __get_cpu_var(var) per_cpu_var(var)
#define __raw_get_cpu_var(var) per_cpu_var(var)
#define per_cpu_ptr(ptr, cpu) (ptr)
+#define __get_cpu_ptr(ptr) (ptr)
+#define __raw_get_cpu_ptr(ptr) (ptr)
#endif /* SMP */
diff -r 0fb05e4271a6 include/linux/percpu.h
--- a/include/linux/percpu.h Mon Nov 17 22:19:40 2008 +1030
+++ b/include/linux/percpu.h Mon Nov 17 22:21:09 2008 +1030
@@ -57,6 +57,22 @@
&__get_cpu_var(var); }))
#define put_cpu_var(var) preempt_enable()
+/**
+ * put_cpu_ptr - return a pointer to this cpu's allocated memory
+ * @ptr: the pointer passed to get_cpu_ptr().
+ *
+ * Counterpart to get_cpu_ptr(): re-enables preemption
+ */
+#define put_cpu_ptr(ptr) preempt_enable()
+
+/**
+ * get_cpu_ptr - hold a pointer to this cpu's allocated memory
+ * @ptr: the pointer returned from alloc_percpu
+ *
+ * Similar to get_cpu_var(), except for dynamic memory. Disabled preemption.
+ */
+#define get_cpu_ptr(ptr) ({ preempt_disable(); __get_cpu_ptr(ptr); })
+
#ifdef CONFIG_SMP
void *__alloc_percpu(unsigned long size, unsigned long align);
void free_percpu(void *pcpuptr);
--
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