Add a __ksize() equivalent for vmalloc.
This is being added so we can track amount of memory stranded waiting
for an RCU grace period.
Cc: linux-mm@xxxxxxxxx
Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
include/linux/vmalloc.h | 1 +
mm/vmalloc.c | 20 ++++++++++++++++++++
2 files changed, 21 insertions(+)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index c720be70c8dd..3a6e29de8818 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -160,6 +160,7 @@ extern void *vcalloc(size_t n, size_t size) __alloc_size(1, 2);
extern void vfree(const void *addr);
extern void vfree_atomic(const void *addr);
+extern size_t vmalloc_bytes(const void *addr);
extern void *vmap(struct page **pages, unsigned int count,
unsigned long flags, pgprot_t prot);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index d12a17fc0c17..3642fca84c34 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2848,6 +2848,26 @@ void vfree(const void *addr)
}
EXPORT_SYMBOL(vfree);
+/**
+ * vmalloc_bytes - Return size of a vmalloc() allocation
+ * @addr: Memory base address
+ *
+ * Returns the size of the allocation as passed to vmalloc() rounded up to
+ * PAGE_SIZE; does not include extra internal allocations.
+ */
+size_t vmalloc_bytes(const void *addr)
+{
+ struct vm_struct *vm = find_vm_area(addr);
+ if (unlikely(!vm)) {
+ WARN(1, KERN_ERR "vmalloc_bytes() called on nonexistent vm area (%p)\n",
+ addr);
+ return 0;
+ }
+
+ return vm->nr_pages * PAGE_SIZE;
+}
+EXPORT_SYMBOL(vmalloc_bytes);
+
/**
* vunmap - release virtual mapping obtained by vmap()
* @addr: memory base address
--
2.43.0
