| Message ID | 20240227072515.3736069-1-kent.overstreet@linux.dev (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] mm: vmalloc_bytes() | expand |
On Tue, 27 Feb 2024 02:25:14 -0500 Kent Overstreet <kent.overstreet@linux.dev> wrote: > Add a __ksize() equivalent for vmalloc. > +++ 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; if (WARN(!vm, "...")) and I don't think the explicit KERN_ERR facility is needed?
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
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@kvack.org Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> --- include/linux/vmalloc.h | 1 + mm/vmalloc.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+)