Messages in this thread | | | Date | Fri, 16 Nov 2018 13:55:51 +0800 | From | Herbert Xu <> | Subject | Re: [PATCH] rhashtable: detect when object movement between tables might have invalidated a lookup |
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On Thu, Nov 15, 2018 at 10:32:13AM +1100, NeilBrown wrote: > > +#define RHT_NULLS_MARKER(ptr) \ > + ((void *)NULLS_MARKER(((unsigned long) (ptr)) >> 1)) > #define INIT_RHT_NULLS_HEAD(ptr) \ > - ((ptr) = (typeof(ptr)) NULLS_MARKER(0)) > + ((ptr) = RHT_NULLS_MARKER(&(ptr)))
Why are you shifting this by one?
> diff --git a/lib/rhashtable.c b/lib/rhashtable.c > index 30526afa8343..852ffa5160f1 100644 > --- a/lib/rhashtable.c > +++ b/lib/rhashtable.c > @@ -1179,8 +1179,7 @@ struct rhash_head __rcu **rht_bucket_nested(const struct bucket_table *tbl, > unsigned int hash) > { > const unsigned int shift = PAGE_SHIFT - ilog2(sizeof(void *)); > - static struct rhash_head __rcu *rhnull = > - (struct rhash_head __rcu *)NULLS_MARKER(0); > + static struct rhash_head __rcu *rhnull;
I don't understand why you can't continue to do NULLS_MARKER(0) or RHT_NULLS_MARKER(0).
Cheers, -- Email: Herbert Xu <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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