Re: [PATCH - revised] rhashtable: detect when object movement might have invalidated a lookup

NeilBrown
2018-07-20T06:24:16Z

[-- Attachment #1: Type: text/plain, Size: 929 bytes --]

On Tue, Jul 17 2018, Herbert Xu wrote:

> On Mon, Jul 16, 2018 at 01:26:42PM +1000, NeilBrown wrote:
>>
>> Look in Documenation/RCU/rculist_nulls.txt.
>> The very first example is a typical lookup for a nulls list.
>> The above sample code would read:
>
> OK, but how will this work with rhlist? It would be very bad to
> have a feature that works for rhashtable but fails in strange
> ways when you use rhlist.

It should be easy enough to handle in rhlist too.
When inserting a new object, we put it at the start of the chain, and if
there was already a list with the same key, it gets moved to
the new object.
A walk could see some objects repeatedly when this happens, but that
is already possible.

Thanks,
NeilBrown

>
> 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

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]