linux-kernel - Re: [PATCH v2] rcu: Allow to eliminate softirq processing from rcutree

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: <20190320175952.yh6yfy64vaiurszw@linutronix.de>
Date:   Wed, 20 Mar 2019 18:59:52 +0100
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     "Paul E. McKenney" <paulmck@...ux.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>,
        Joel Fernandes <joel@...lfernandes.org>, tglx@...utronix.de,
        Mike Galbraith <efault@....de>
Subject: Re: [PATCH v2] rcu: Allow to eliminate softirq processing from
 rcutree

On 2019-03-20 10:30:01 [-0700], Paul E. McKenney wrote:
> On Wed, Mar 20, 2019 at 05:35:32PM +0100, Sebastian Andrzej Siewior wrote:
> > On 2019-03-20 09:15:00 [-0700], Paul E. McKenney wrote:
> > > I am considering making it a module_param() to avoid namespace pollution,
> > > as it would become something like rcutree.nosoftirq.
> > > 
> > > Thoughts?
> > 
> > nope, perfect.
> 
> Please see below for an untested patch.  Thoughts?

> -	if (rcu_softirq_enabled) {
> +	if (!nosoftirq) {
>  		raise_softirq(RCU_SOFTIRQ);
>  	} else {

This double negation looks weird. Can we flip the logic somehow?
/me testing if it works…
> 							Thanx, Paul

Sebastian