From: Jiri Pirko <jiri@resnulli.us>
To: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Cc: jiri@mellanox.com, davem@davemloft.net, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, joel@joelfernandes.org,
frextrite@gmail.com,
linux-kernel-mentees@lists.linuxfoundation.org,
paulmck@kernel.org
Subject: Re: [PATCH] net: core: devlink.c: Use built-in RCU list checking
Date: Fri, 21 Feb 2020 18:54:36 +0100 [thread overview]
Message-ID: <20200221175436.GB2181@nanopsycho> (raw)
In-Reply-To: <20200221173533.GA13198@madhuparna-HP-Notebook>
Fri, Feb 21, 2020 at 06:35:34PM CET, madhuparnabhowmik10@gmail.com wrote:
>On Fri, Feb 21, 2020 at 06:20:08PM +0100, Jiri Pirko wrote:
>> Fri, Feb 21, 2020 at 05:51:41PM CET, madhuparnabhowmik10@gmail.com wrote:
>> >From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>> >
>> >list_for_each_entry_rcu() has built-in RCU and lock checking.
>> >
>> >Pass cond argument to list_for_each_entry_rcu() to silence
>> >false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
>> >by default.
>> >
>> >Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>>
>> Reviewed-by: Jiri Pirko <jiri@mellanox.com>
>>
>> Thanks.
>>
>> However, there is a callpath where not devlink lock neither rcu read is
>> taken:
>> devlink_dpipe_table_register()->devlink_dpipe_table_find()
>>
>Hi,
>
>Yes I had noticed this, but I was not sure if there is some other lock
>which is being used.
>
>If yes, then can you please tell me which lock is held in this case,
>and I can add that condition as well to list_for_each_entry_rcu() usage.
>
>And if no lock or rcu_read_lock is held then may be we should
>use rcu_read_lock/unlock here.
>
>Let me know what you think about this.
devlink->lock should be held since the beginning of
devlink_dpipe_table_register()
next prev parent reply other threads:[~2020-02-21 17:54 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 16:51 [PATCH] net: core: devlink.c: Use built-in RCU list checking madhuparnabhowmik10
2020-02-21 17:20 ` Jiri Pirko
2020-02-21 17:35 ` Madhuparna Bhowmik
2020-02-21 17:54 ` Jiri Pirko [this message]
2020-02-21 18:00 ` Madhuparna Bhowmik
2020-02-23 11:03 ` Madhuparna Bhowmik
2020-02-23 18:19 ` Jiri Pirko
2020-02-24 0:28 ` kbuild test robot
-- strict thread matches above, loose matches on Subject: below --
2020-02-24 9:30 madhuparnabhowmik10
2020-02-24 10:52 ` Jiri Pirko
2020-02-25 12:09 ` Madhuparna Bhowmik
2020-02-25 12:27 madhuparnabhowmik10
2020-02-25 13:06 ` Jiri Pirko
2020-02-27 0:59 ` David Miller
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