This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-devel] Re: Question about x86/mm/gup.c's use of disabled interrupts

To: paulmck@xxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] Re: Question about x86/mm/gup.c's use of disabled interrupts
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Fri, 20 Mar 2009 08:38:46 -0700
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Linux Memory Management List <linux-mm@xxxxxxxxx>, Avi Kivity <avi@xxxxxxxxxx>, Ingo Molnar <mingo@xxxxxxx>
Delivery-date: Fri, 20 Mar 2009 08:39:14 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20090320044029.GD6807@xxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <49C148AF.5050601@xxxxxxxx> <200903191232.05459.nickpiggin@xxxxxxxxxxxx> <49C2818B.9060201@xxxxxxxx> <20090320044029.GD6807@xxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird (X11/20090105)
Paul E. McKenney wrote:
Ah, interesting. So disabling interrupts prevents the RCU free from happening, and non-atomic pte fetching is a non-issue. So it doesn't address the PAE side of the problem.

This would be rcu_sched, correct?

I guess? Whatever it is that ends up calling all the rcu callbacks after the idle. A cpu with disabled interrupts can't go through idle, right? Or is there an explicit way to hold off rcu?


Xen-devel mailing list