linux-kernel - Re: [PATCH RFC tip/core/rcu] Parallelize and economize NOCB kthread wakeups

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: <1404366520.5137.90.camel@marge.simpson.net>
Date:	Thu, 03 Jul 2014 07:48:40 +0200
From:	Mike Galbraith <umgwanakikbuti@...il.com>
To:	paulmck@...ux.vnet.ibm.com
Cc:	Peter Zijlstra <peterz@...radead.org>,
	linux-kernel@...r.kernel.org, riel@...hat.com, mingo@...nel.org,
	laijs@...fujitsu.com, dipankar@...ibm.com,
	akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
	josh@...htriplett.org, niv@...ibm.com, tglx@...utronix.de,
	rostedt@...dmis.org, dhowells@...hat.com, edumazet@...gle.com,
	dvhart@...ux.intel.com, fweisbec@...il.com, oleg@...hat.com,
	sbw@....edu
Subject: Re: [PATCH RFC tip/core/rcu] Parallelize and economize NOCB kthread
 wakeups

On Wed, 2014-07-02 at 22:21 -0700, Paul E. McKenney wrote: 
> On Thu, Jul 03, 2014 at 05:31:19AM +0200, Mike Galbraith wrote:

> > NO_HZ_FULL is a property of a set of CPUs.  isolcpus is supposed to go
> > away as being a redundant interface to manage a single property of a set
> > of CPUs, but it's perfectly fine for NO_HZ_FULL to add an interface to
> > manage a single property of a set of CPUs.  What am I missing? 
> 
> Well, for now, it can only be specified at build time or at boot time.
> In theory, it is possible to change a CPU from being callback-offloaded
> to not at runtime, but there would need to be an extremely good reason
> for adding that level of complexity.  Lots of "fun" races in there...

Yeah, understood.

(still it's a NO_HZ_FULL wart though IMHO, would be prettier and more
usable if it eventually became unified with cpuset and learned how to
tap-dance properly;)

-Mike

--
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/