percpu: don't implicitly include slab.h from percpu.h

percpu.h has always been including slab.h to get k[mz]alloc/free() for UP inline implementation. percpu.h being used by very low level headers including module.h and sched.h, this meant that a lot files unintentionally got slab.h inclusion. Lee Schermerhorn was trying to make topology.h use percpu.h and got bitten by this implicit inclusion. The right thing to do is break this ultimately unnecessary dependency. The previous patch added explicit inclusion of either gfp.h or slab.h to the source files using them. This patch updates percpu.h such that slab.h is no longer included from percpu.h. Signed-off-by: Tejun Heo <[email protected]> Reviewed-by: Christoph Lameter <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Lee Schermerhorn <[email protected]>
csanz · Mar 30, 2010 · de380b5 · de380b5
1 parent ea5a9f0
commit de380b5
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Showing 3 changed files with 40 additions and 26 deletions.
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
@@ -2,10 +2,10 @@
 #define __LINUX_PERCPU_H
 
 #include <linux/preempt.h>
-#include <linux/slab.h> /* For kmalloc() */
 #include <linux/smp.h>
 #include <linux/cpumask.h>
 #include <linux/pfn.h>
+#include <linux/init.h>
 
 #include <asm/percpu.h>
 
@@ -135,9 +135,6 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size,
 #define per_cpu_ptr(ptr, cpu)	SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
 
 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
-extern void __percpu *__alloc_percpu(size_t size, size_t align);
-extern void free_percpu(void __percpu *__pdata);
-extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 
 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
 extern void __init setup_per_cpu_areas(void);
@@ -147,27 +144,6 @@ extern void __init setup_per_cpu_areas(void);
 
 #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
 
-static inline void __percpu *__alloc_percpu(size_t size, size_t align)
-{
-	/*
-	 * Can't easily make larger alignment work with kmalloc.  WARN
-	 * on it.  Larger alignment should only be used for module
-	 * percpu sections on SMP for which this path isn't used.
-	 */
-	WARN_ON_ONCE(align > SMP_CACHE_BYTES);
-	return kzalloc(size, GFP_KERNEL);
-}
-
-static inline void free_percpu(void __percpu *p)
-{
-	kfree(p);
-}
-
-static inline phys_addr_t per_cpu_ptr_to_phys(void *addr)
-{
-	return __pa(addr);
-}
-
 static inline void __init setup_per_cpu_areas(void) { }
 
 static inline void *pcpu_lpage_remapped(void *kaddr)
@@ -177,6 +153,10 @@ static inline void *pcpu_lpage_remapped(void *kaddr)
 
 #endif /* CONFIG_SMP */
 
+extern void __percpu *__alloc_percpu(size_t size, size_t align);
+extern void free_percpu(void __percpu *__pdata);
+extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
+
 #define alloc_percpu(type)	\
 	(typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
 

diff --git a/mm/Makefile b/mm/Makefile
@@ -33,7 +33,11 @@ obj-$(CONFIG_FAILSLAB) += failslab.o
 obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
 obj-$(CONFIG_FS_XIP) += filemap_xip.o
 obj-$(CONFIG_MIGRATION) += migrate.o
-obj-$(CONFIG_SMP) += percpu.o
+ifdef CONFIG_SMP
+obj-y += percpu.o
+else
+obj-y += percpu_up.o
+endif
 obj-$(CONFIG_QUICKLIST) += quicklist.o
 obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
 obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o

diff --git a/mm/percpu_up.c b/mm/percpu_up.c
@@ -0,0 +1,30 @@
+/*
+ * mm/percpu_up.c - dummy percpu memory allocator implementation for UP
+ */
+
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
+
+void __percpu *__alloc_percpu(size_t size, size_t align)
+{
+	/*
+	 * Can't easily make larger alignment work with kmalloc.  WARN
+	 * on it.  Larger alignment should only be used for module
+	 * percpu sections on SMP for which this path isn't used.
+	 */
+	WARN_ON_ONCE(align > SMP_CACHE_BYTES);
+	return kzalloc(size, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(__alloc_percpu);
+
+void free_percpu(void __percpu *p)
+{
+	kfree(p);
+}
+EXPORT_SYMBOL_GPL(free_percpu);
+
+phys_addr_t per_cpu_ptr_to_phys(void *addr)
+{
+	return __pa(addr);
+}