linux-kernel - Re: [PATCH 2/4] sched: Isolate preempt counting in its own config option

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: <1307563754.2497.999.camel@laptop>
Date:	Wed, 08 Jun 2011 22:09:14 +0200
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	paulmck@...ux.vnet.ibm.com
Cc:	Frederic Weisbecker <fweisbec@...il.com>,
	LKML <linux-kernel@...r.kernel.org>, Ingo Molnar <mingo@...e.hu>
Subject: Re: [PATCH 2/4] sched: Isolate preempt counting in its own config
 option

On Wed, 2011-06-08 at 12:58 -0700, Paul E. McKenney wrote:
> 
> On Wed, Jun 08, 2011 at 09:47:14PM +0200, Peter Zijlstra wrote:
> > On Wed, 2011-06-08 at 19:48 +0200, Frederic Weisbecker wrote:
> > > 
> > > Create a new CONFIG_PREEMPT_COUNT that handles the inc/dec
> > > of preempt count offset independently. So that the offset
> > > can be updated by preempt_disable() and preempt_enable()
> > > even without the need for CONFIG_PREEMPT beeing set.
> > > 
> > > This prepares to make CONFIG_DEBUG_SPINLOCK_SLEEP working
> > > with !CONFIG_PREEMPT where it currently doesn't detect
> > > code that sleeps inside explicit preemption disabled
> > > sections. 
> > 
> > The last time this got proposed it got shot down due to the extra
> > inc/dec stuff all over the place increasing overhead significantly.
> 
> Even given that the extra inc/dec stuff only happens in kernels built
> with DEBUG_SPINLOCK_SLEEP=y (DEBUG_ATOMIC_SLEEP=y after patch 4/4)? 

Ah, no that might be ok. That's what I get for trying to read email in
no time.


--
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/