Re: [PATCH] mm/z3fold.c: Allow __GFP_HIGHMEM in z3fold_alloc

From: Shakeel Butt
Date: Sat Jul 13 2019 - 12:05:42 EST


On Fri, Jul 12, 2019 at 3:22 PM Henry Burns <henryburns@xxxxxxxxxx> wrote:
>
> One of the gfp flags used to show that a page is movable is
> __GFP_HIGHMEM. Currently z3fold_alloc() fails when __GFP_HIGHMEM is
> passed. Now that z3fold pages are movable, we allow __GFP_HIGHMEM. We
> strip the movability related flags from the call to kmem_cache_alloc()
> for our slots since it is a kernel allocation.
>
> Signed-off-by: Henry Burns <henryburns@xxxxxxxxxx>

Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>

> ---
> mm/z3fold.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/mm/z3fold.c b/mm/z3fold.c
> index e78f95284d7c..cb567ddf051c 100644
> --- a/mm/z3fold.c
> +++ b/mm/z3fold.c
> @@ -193,7 +193,8 @@ static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool,
> gfp_t gfp)
> {
> struct z3fold_buddy_slots *slots = kmem_cache_alloc(pool->c_handle,
> - gfp);
> + (gfp & ~(__GFP_HIGHMEM
> + | __GFP_MOVABLE)));
>
> if (slots) {
> memset(slots->slot, 0, sizeof(slots->slot));
> @@ -844,7 +845,7 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
> enum buddy bud;
> bool can_sleep = gfpflags_allow_blocking(gfp);
>
> - if (!size || (gfp & __GFP_HIGHMEM))
> + if (!size)
> return -EINVAL;
>
> if (size > PAGE_SIZE)
> --
> 2.22.0.510.g264f2c817a-goog
>