[PATCH -stable] vmalloc: conditionalize build of pcpu_get_vm_areas()

Tejun Heo
2009-12-09T23:43:16Z

pcpu_get_vm_areas() is used only when dynamic percpu allocator is used
by the architecture. In 2.6.32, ia64 doesn't use dynamic percpu
allocator and has a macro which makes pcpu_get_vm_areas() buggy via
local/global variable aliasing and triggers compile warning.

The problem is fixed in upstream and ia64 uses dynamic percpu
allocators, so the only left issue is inclusion of unnecessary code
and compile warning on ia64 on 2.6.32.

Don't build pcpu_get_vm_areas() if legacy percpu allocator is in use.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jan Beulich <JBeulich@novell.com>
Cc: stable@kernel.org
---
Please note that this commit won't appear on upstream.

Thanks.

include/linux/vmalloc.h | 2 ++
mm/vmalloc.c | 2 ++
2 files changed, 4 insertions(+)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 227c2a5..3c123c3 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -115,9 +115,11 @@ extern rwlock_t vmlist_lock;
extern struct vm_struct *vmlist;
extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);

+#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
const size_t *sizes, int nr_vms,
size_t align, gfp_t gfp_mask);
+#endif

void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 0f551a4..7758726 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1993,6 +1993,7 @@ void free_vm_area(struct vm_struct *area)
}
EXPORT_SYMBOL_GPL(free_vm_area);

+#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
static struct vmap_area *node_to_va(struct rb_node *n)
{
return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
@@ -2257,6 +2258,7 @@ err_free:
kfree(vms);
return NULL;
}
+#endif

/**
* pcpu_free_vm_areas - free vmalloc areas for percpu allocator