linux-kernel - Re: [PATCH RFC 5/8] rcu: Use rcu_node as temporary variable in funnel locking loop

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180515004334.GC209519@joelaf.mtv.corp.google.com>
Date:   Mon, 14 May 2018 17:43:34 -0700
From:   Joel Fernandes <joel@...lfernandes.org>
To:     "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc:     linux-kernel@...r.kernel.org,
        Josh Triplett <josh@...htriplett.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Lai Jiangshan <jiangshanlai@...il.com>, byungchul.park@....com,
        kernel-team@...roid.com
Subject: Re: [PATCH RFC 5/8] rcu: Use rcu_node as temporary variable in
 funnel locking loop

On Mon, May 14, 2018 at 11:00:27AM -0700, Paul E. McKenney wrote:
> On Sun, May 13, 2018 at 08:15:38PM -0700, Joel Fernandes (Google) wrote:
> > The funnel locking loop in rcu_start_this_gp uses rcu_root as a
> > temporary variable while walking the combining tree. This causes a
> > tiresome exercise of a code reader reminding themselves that rcu_root
> > may not be root. Lets just call it rcu_node, and then finally when
> > rcu_node is the rcu_root, lets assign it at that time.
> > 
> > Just a clean up patch, no logical change.
> > 
> > Signed-off-by: Joel Fernandes (Google) <joel@...lfernandes.org>
> 
> I agree that my names could use some improvement, but given that you
> called it rnp_node in the patch and rcu_node in the commit log, I would
> argue that rnp_node has a Hamming-distance problem.  ;-)
> 
> How about rnp_start for the formal parameter, rnp for the cursor running
> up the tree, and retaining rnp_root for the root?

Ok, that's fine with me. Probably easier to read too. I will rewrite it
accordingly.

thanks,

- Joel