Re: rhashtable: Prevent spurious EBUSY errors on insertion

From	Herbert Xu <herbert@gondor.apana.org.au>
Newsgroups	linux.kernel
Subject	Re: rhashtable: Prevent spurious EBUSY errors on insertion
Date	2015-12-17 09:50 +0100
Message-ID	<qGCq6-5pv-17@gated-at.bofh.it> (permalink)
References	(1 earlier) <qAt6b-1Ny-17@gated-at.bofh.it> <qAtIR-2gq-1@gated-at.bofh.it> <qAtIR-2gq-15@gated-at.bofh.it> <qBBuH-53y-37@gated-at.bofh.it> <qGCq6-5pv-19@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Thu, Dec 17, 2015 at 04:46:00PM +0800, Xin Long wrote:
>
> sorry for late test, but unfortunately, my case with rhashtalbe still
> return EBUSY.
> I added some debug code in rhashtable_insert_rehash(), and found:
> *future_tbl is null*
> 
> fail:
>         /* Do not fail the insert if someone else did a rehash. */
>         if (likely(rcu_dereference_raw(tbl->future_tbl))) {
>                 printk("future_tbl is there\n");
>                 return 0;
>         } else {
>                 printk("future_tbl is null\n");
>         }
> 
> any idea why ?

That's presumably because you got a genuine double rehash.

Until you post your code we can't really help you.

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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: rhashtable: Prevent spurious EBUSY errors on insertion Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-17 09:50 +0100
  Re: rhashtable: Prevent spurious EBUSY errors on insertion Xin Long <lucien.xin@gmail.com> - 2015-12-17 10:10 +0100
    Re: rhashtable: Prevent spurious EBUSY errors on insertion Xin Long <lucien.xin@gmail.com> - 2015-12-17 17:10 +0100
      Re: rhashtable: Prevent spurious EBUSY errors on insertion Herbert Xu <herbert@gondor.apana.org.au> - 2015-12-18 03:30 +0100
        Re: rhashtable: Prevent spurious EBUSY errors on insertion Xin Long <lucien.xin@gmail.com> - 2015-12-18 09:20 +0100
    Re: rhashtable: Prevent spurious EBUSY errors on insertion David Miller <davem@davemloft.net> - 2015-12-17 18:10 +0100

csiph-web