Re: [PATCH] mm/vmalloc: Separate put pages and flush VM flags
From: Miaohe Lin
Date: Thu Jan 21 2021 - 01:03:43 EST
On 2021/1/21 9:41, Rick Edgecombe wrote:
> When VM_MAP_PUT_PAGES was added, it was defined with the same value as
> VM_FLUSH_RESET_PERMS. This doesn't seem like it will cause any big
> functional problems other than some excess flushing for VM_MAP_PUT_PAGES
> Redefine VM_MAP_PUT_PAGES to have its own value. Also, move the comment
> and remove whitespace for VM_KASAN such that the flags lower down are less
> likely to be missed in the future.
>> Fixes: b944afc9d64d ("mm: add a VM_MAP_PUT_PAGES flag for vmap")
Is this worth a Cc stable ?
> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> include/linux/vmalloc.h | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
> diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> index 80c0181c411d..0b3dd135aa5d 100644
> --- a/include/linux/vmalloc.h
> +++ b/include/linux/vmalloc.h
> @@ -23,9 +23,6 @@ struct notifier_block; /* in notifier.h */
> #define VM_DMA_COHERENT 0x00000010 /* dma_alloc_coherent */
> #define VM_UNINITIALIZED 0x00000020 /* vm_struct is not fully initialized */
> #define VM_NO_GUARD 0x00000040 /* don't add guard page */
> -#define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */
> -#define VM_MAP_PUT_PAGES 0x00000100 /* put pages and free array in vfree */
> * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC.
> @@ -36,12 +33,13 @@ struct notifier_block; /* in notifier.h */
> * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to
> * determine which allocations need the module shadow freed.
> +#define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */
> * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with
> * vfree_atomic().
> #define VM_FLUSH_RESET_PERMS 0x00000100 /* Reset direct map and flush TLB on unmap */
> +#define VM_MAP_PUT_PAGES 0x00000200 /* put pages and free array in vfree */
> /* bits [20..32] reserved for arch specific ioremap internals */
Looks good to me.
Reviewed-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>