> On Jun 23, 2022, at 6:56 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Jun 22, 2022 at 10:15:50AM -0400, Chuck Lever wrote:
>
>> +static u32 nfsd_file_obj_hashfn(const void *data, u32 len, u32 seed)
>> +{
>> + const struct nfsd_file *nf = data;
>> +
>> + return jhash2((const u32 *)&nf->nf_inode,
>> + sizeof_field(struct nfsd_file, nf_inode) / sizeof(u32),
>> + seed);
>
> Out of curiosity - what are you using to allocate those? Because if
> it's a slab, then middle bits of address (i.e. lower bits of
> (unsigned long)data / L1_CACHE_BYTES) would better be random enough...
261 static struct nfsd_file *
262 nfsd_file_alloc(struct nfsd_file_lookup_key *key, unsigned int may)
263 {
264 static atomic_t nfsd_file_id;
265 struct nfsd_file *nf;
266
267 nf = kmem_cache_alloc(nfsd_file_slab, GFP_KERNEL);
Was wondering about that. pahole says struct nfsd_file is 112
bytes on my system.
--
Chuck Lever
