Re: [rhashtable] [ INFO: suspicious RCU usage. ]

From: Herbert Xu
Date: Wed Apr 01 2015 - 23:58:24 EST


On Thu, Apr 02, 2015 at 08:52:11AM +0800, Fengguang Wu wrote:
> Hi Herbert,
>
> 0day kernel testing robot got the below dmesg and the first bad commit is
>
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
>
> commit ccd57b1bd32460d27bbb9c599e795628a3c66983
> Author: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> AuthorDate: Tue Mar 24 00:50:28 2015 +1100
> Commit: David S. Miller <davem@xxxxxxxxxxxxx>
> CommitDate: Mon Mar 23 22:07:52 2015 -0400
>
> rhashtable: Add immediate rehash during insertion
>
> This patch reintroduces immediate rehash during insertion. If
> we find during insertion that the table is full or the chain
> length exceeds a set limit (currently 16 but may be disabled
> with insecure_elasticity) then we will force an immediate rehash.
> The rehash will contain an expansion if the table utilisation
> exceeds 75%.
>
> If this rehash fails then the insertion will fail. Otherwise the
> insertion will be reattempted in the new hash table.
>
> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Acked-by: Thomas Graf <tgraf@xxxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
>
> [ 0.552992] Adding 2048 keys
> [ 0.553792]
> [ 0.554400] ===============================
> [ 0.555285] [ INFO: suspicious RCU usage. ]
> [ 0.556176] 4.0.0-rc4-01225-gccd57b1 #171 Not tainted
> [ 0.557156] -------------------------------
> [ 0.558044] lib/rhashtable.c:400 suspicious rcu_dereference_check() usage!

This should have been fixed by

58be8a583d8d316448bafa5926414cfb83c02dec.

Can you check whether this commit was in your tested tree?

Thanks,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/