linux-kernel - Re: [RFC][PATCH] module: Optimize __module

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]

Date:	Sat, 28 Feb 2015 15:32:03 -0800
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Andi Kleen <ak@...ux.intel.com>,
	Andi Kleen <andi@...stfloor.org>, x86@...nel.org,
	linux-kernel@...r.kernel.org, oleg@...hat.com,
	rusty@...tcorp.com.au, mingo@...nel.org
Subject: Re: [RFC][PATCH] module: Optimize __module_address() using a latched
 RB-tree

On Sat, Feb 28, 2015 at 05:56:54PM +0100, Peter Zijlstra wrote:
> On Sat, Feb 28, 2015 at 05:41:12PM +0100, Peter Zijlstra wrote:
> > > > > +	rb_link_node(&mn->node, parent, link);
> > > > 
> > > > This makes the new module visible to readers, if I understand correctly.
> > > 
> > > You do.
> > 
> > I think I have reconsidered; this does not in fact make it visible.
> 
> Ah; never mind, it is. An iterator could have started in data[0], gone
> on holiday while the modification took place, and resumed once it is
> done and magically see the element appear.
> 
> Therefore we do indeed need the atomic publishing and I think this also
> settles my question about Alpha.

Whew!

Though otherwise whatever you were doing would have been pretty cool
and fun to learn about.  ;-)

							Thanx, Paul

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/