netdev - Re: [PATCH] net: batman-adv: Use built-in RCU list checking

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Message-ID: <20200217120524.GA12888@madhuparna-HP-Notebook>
Date:   Mon, 17 Feb 2020 17:35:25 +0530
From:   Madhuparna Bhowmik <madhuparnabhowmik10@...il.com>
To:     Sven Eckelmann <sven@...fation.org>
Cc:     Madhuparna Bhowmik <madhuparnabhowmik10@...il.com>,
        mareklindner@...mailbox.ch, sw@...onwunderlich.de, a@...table.cc,
        davem@...emloft.net, b.a.t.m.a.n@...ts.open-mesh.org,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        joel@...lfernandes.org, frextrite@...il.com,
        linux-kernel-mentees@...ts.linuxfoundation.org
Subject: Re: [PATCH] net: batman-adv: Use built-in RCU list checking

On Sun, Feb 16, 2020 at 05:17:36PM +0100, Sven Eckelmann wrote:
> On Sunday, 16 February 2020 16:52:44 CET Madhuparna Bhowmik wrote:
> [...]
> > > I understand this part. I was asking how you've identified them. Did you use 
> > > any tool for that? coccinelle, sparse, ...
> > 
> > Not really, I did it manually by inspecting each occurence.
> 
> In that case, I don't understand why you didn't convert the occurrences from 
> hlist_for_each_entry_rcu to hlist_for_each_entry [1]. Because a manual
> inspection should have noticed that there will always be the lock around
> these ones.
>
Hi Sven,
I have been working on similar issues (passing cond argument to
list_for_each_entry_Rcu()). That's why may be I didn't notice that in
this case rcu variant is not required.
Thank you for taking a closer look and fixing it the right way.

Regards,
Madhuparna

> KInd regards,
> 	Sven
> 
> [1] https://www.kernel.org/doc/html/v5.6-rc1/RCU/whatisRCU.html#analogy-with-reader-writer-locking