From: Herbert Xu <herbert@gondor.apana.org.au>
To: Xin Long <lucien.xin@gmail.com>
Cc: Phil Sutter <phil@nwl.cc>, davem <davem@davemloft.net>,
network dev <netdev@vger.kernel.org>,
linux-kernel@vger.kernel.org, tgraf@suug.ch,
fengguang.wu@intel.com, wfg@linux.intel.com, lkp@01.org
Subject: Re: rhashtable: Prevent spurious EBUSY errors on insertion
Date: Thu, 17 Dec 2015 16:48:09 +0800 [thread overview]
Message-ID: <20151217084809.GC9239@gondor.apana.org.au> (raw)
In-Reply-To: <CADvbK_cA5qaooTOE4Z2bGYs+ys17ZajSMgKDVWgctSZWJ0vjpw@mail.gmail.com>
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
next prev parent reply other threads:[~2015-12-17 8:48 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-20 17:17 [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test Phil Sutter
2015-11-20 17:17 ` [PATCH v2 1/4] rhashtable-test: add cond_resched() to thread test Phil Sutter
2015-11-20 17:17 ` [PATCH v2 2/4] rhashtable-test: retry insert operations Phil Sutter
2015-11-20 17:17 ` [PATCH v2 3/4] rhashtable-test: calculate max_entries value by default Phil Sutter
2015-11-20 17:17 ` [PATCH v2 4/4] rhashtable-test: allow to retry even if -ENOMEM was returned Phil Sutter
2015-11-20 17:28 ` Phil Sutter
2015-11-23 17:38 ` [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test David Miller
2015-11-30 9:37 ` Herbert Xu
2015-11-30 10:14 ` Phil Sutter
2015-11-30 10:18 ` Herbert Xu
2015-12-03 12:41 ` rhashtable: Prevent spurious EBUSY errors on insertion Herbert Xu
2015-12-03 15:38 ` Phil Sutter
2015-12-04 19:38 ` David Miller
2015-12-17 8:46 ` Xin Long
2015-12-17 8:48 ` Herbert Xu [this message]
2015-12-17 9:00 ` Xin Long
2015-12-17 16:07 ` Xin Long
2015-12-18 2:26 ` Herbert Xu
2015-12-18 8:18 ` Xin Long
2015-12-17 17:00 ` David Miller
2015-12-03 12:51 ` rhashtable: ENOMEM errors when hit with a flood of insertions Herbert Xu
2015-12-03 15:08 ` David Laight
2015-12-03 16:08 ` Eric Dumazet
2015-12-04 0:07 ` Herbert Xu
2015-12-04 14:39 ` rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Herbert Xu
2015-12-04 17:01 ` Phil Sutter
2015-12-04 17:45 ` Eric Dumazet
2015-12-04 18:15 ` Phil Sutter
2015-12-05 7:06 ` Herbert Xu
2015-12-07 15:35 ` Thomas Graf
2015-12-07 19:29 ` David Miller
2015-12-09 2:18 ` Thomas Graf
2015-12-09 2:24 ` Herbert Xu
2015-12-09 2:36 ` Thomas Graf
2015-12-09 2:38 ` Herbert Xu
2015-12-09 2:42 ` Thomas Graf
2015-12-04 21:53 ` David Miller
2015-12-05 7:03 ` Herbert Xu
2015-12-06 3:48 ` David Miller
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