From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
To: Jiri Pirko <jiri@resnulli.us>, y@madhuparna-HP-Notebook
Cc: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>,
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 23:30:15 +0530 [thread overview]
Message-ID: <20200221180015.GA16779@madhuparna-HP-Notebook> (raw)
In-Reply-To: <20200221175436.GB2181@nanopsycho>
On Fri, Feb 21, 2020 at 06:54:36PM +0100, Jiri Pirko wrote:
> 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()
>
Alright, I will send a patch with this change soon.
Thank you for the help.
Regards,
Madhuparna
next prev parent reply other threads:[~2020-02-21 18:00 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
2020-02-21 18:00 ` Madhuparna Bhowmik [this message]
2020-02-23 11:03 ` Madhuparna Bhowmik
2020-02-23 18:19 ` Jiri Pirko
2020-02-24 0:28 ` kbuild test robot
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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