linux-kernel - Re: [PATCH RFC] Priority boosting for preemptible RCU

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20070824082121.GA16301@in.ibm.com>
Date:	Fri, 24 Aug 2007 13:51:21 +0530
From:	Gautham R Shenoy <ego@...ibm.com>
To:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc:	linux-kernel@...r.kernel.org, linux-rt-users@...r.kernel.org,
	mingo@...e.hu, akpm@...ux-foundation.org, dipankar@...ibm.com,
	josht@...ux.vnet.ibm.com, tytso@...ibm.com, dvhltc@...ibm.com,
	tglx@...utronix.de
Subject: Re: [PATCH RFC] Priority boosting for preemptible RCU

On Thu, Aug 23, 2007 at 08:55:26AM -0700, Paul E. McKenney wrote:
> > Even if we use another cpumask_t, whenever a cpu goes down or comes up,
> > that will be reflected in this map, no? So what's the additional
> > advantage of using it?
> 
> The additional map allows the code to use something other than the
> lock_cpu_hotplug/unlock_cpu_hotplug, and also is robust against any
> changes to the hotplug synchronization mechanism.  Might well be
> better just to use the current hotplug synchronization mechanism,
> but I was feeling paranoid.  ;-)

If it was doing something more complicated in the critical section other
than summing stuff up, I would probably recommend going for another map
instead of using the current hotplug synchronization. But for this case
the current hotplug synchronization would work just fine.

I can very well understand your paranoia, but let me assure you, you are
not the only one ;-)

Regards
gautham.
> 
> 						Thanx, Paul

-- 
Gautham R Shenoy
Linux Technology Center
IBM India.
"Freedom comes with a price tag of responsibility, which is still a bargain,
because Freedom is priceless!"
-
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/