On Thu, May 24, 2018 at 02:11:31PM -0700, Davidlohr Bueso wrote:
>
> -static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
> - size_t nbuckets,
> - gfp_t gfp)
> +static struct bucket_table *__bucket_table_alloc(struct rhashtable *ht,
> + size_t nbuckets,
> + gfp_t gfp, bool retry)
> {
> struct bucket_table *tbl = NULL;
> size_t size, max_locks;
> int i;
>
> size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]);
> + if (retry) {
> + gfp |= __GFP_NOFAIL;
> + tbl = kzalloc(size, gfp);
> + } /* fall-through */
I'd prefer this logic to be moved to the caller. So just call the
function with GFP_KERNEL | __GFP_NOFAIL.
Of course you need to modify bucket_table_alloc so that it still
treats this as GFP_KERNEL (as opposed to GFP_ATOMIC). That is,
instead of
> if (gfp != GFP_KERNEL)
You will need
if ((gfp & ~__GFP_NOFAIL) != GFP_KERNEL)
> @@ -1067,9 +1086,20 @@ int rhashtable_init(struct rhashtable *ht,
> }
> }
>
> + /*
> + * This is api initialization and thus we need to guarantee the
> + * initial rhashtable allocation. Upon failure, retry with a
> + * smallest possible size, otherwise we exhaust our options with
> + * __GFP_NOFAIL.
> + */
> tbl = bucket_table_alloc(ht, size, GFP_KERNEL);
> - if (tbl == NULL)
> - return -ENOMEM;
> + if (unlikely(tbl == NULL)) {
> + size = HASH_MIN_SIZE;
> +
> + tbl = bucket_table_alloc(ht, size, GFP_KERNEL);
> + if (tbl == NULL)
> + tbl = bucket_table_alloc_retry(ht, size, GFP_KERNEL);
> + }
Perhaps you should also explain here why we don't just try the
minimum size with __GFP_NOFAIL as the second step rather than the
third.
Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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