rhashtable: remove nulls_base and related code.

This "feature" is unused, undocumented, and untested and so doesn't
really belong.  A patch is under development to properly implement
support for detecting when a search gets diverted down a different
chain, which the common purpose of nulls markers.

This patch actually fixes a bug too.  The table resizing allows a
table to grow to 2^31 buckets, but the hash is truncated to 27 bits -
any growth beyond 2^27 is wasteful an ineffective.

This patch results in NULLS_MARKER(0) being used for all chains,
and leaves the use of rht_is_a_null() to test for it.

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
NeilBrown
2018-06-18 12:52:50 +10:00
committed by David S. Miller
parent 0eb71a9da5
commit 9f9a707738
5 changed files with 6 additions and 46 deletions

View File

@@ -83,7 +83,7 @@ static u32 my_hashfn(const void *data, u32 len, u32 seed)
{
const struct test_obj_rhl *obj = data;
return (obj->value.id % 10) << RHT_HASH_RESERVED_SPACE;
return (obj->value.id % 10);
}
static int my_cmpfn(struct rhashtable_compare_arg *arg, const void *obj)
@@ -99,7 +99,6 @@ static struct rhashtable_params test_rht_params = {
.key_offset = offsetof(struct test_obj, value),
.key_len = sizeof(struct test_obj_val),
.hashfn = jhash,
.nulls_base = (3U << RHT_BASE_SHIFT),
};
static struct rhashtable_params test_rht_params_dup = {
@@ -296,8 +295,6 @@ static int __init test_rhltable(unsigned int entries)
if (!obj_in_table)
goto out_free;
/* nulls_base not supported in rhlist interface */
test_rht_params.nulls_base = 0;
err = rhltable_init(&rhlt, &test_rht_params);
if (WARN_ON(err))
goto out_free;