WARNING - OLD ARCHIVES

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/
Xen

xen-devel

[Top] [All Lists]

Re: [Xen-devel] Xen spinlock questions

To: "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Xen spinlock questions
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: 2008年8月15日 13:15:51 +0100
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: 2008年8月15日 05:15:16 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C4C78034.1C223%keir.fraser@xxxxxxxxxxxxx>
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: <48A1BB46.2080304@xxxxxxxx> <C4C78034.1C223%keir.fraser@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
>>> Keir Fraser <keir.fraser@xxxxxxxxxxxxx> 12.08.08 19:00 >>>
>On 12/8/08 17:33, "Jeremy Fitzhardinge" <jeremy@xxxxxxxx> wrote:
>
>>>> That seems reasonable. In this use-case, it's quite likely that if the
>>>> poll is interrupted by event delivery, on return it will find that the
>>>> spinlock is now free and never re-enter the poll.
>>>> 
>>> 
>>> Attached is a new version of the patch which clears the vcpu from poll_mask
>>> when it is unblocked for any reason. Jan: please can you give this one a
>>> spin if you get time.
>>> 
>> 
>> Forgot to attach?
>
>Sorry, attached now.
I can't really explain the results of testing with this version of the patch:
While the number of false wakeups got further reduced by somewhat
less than 20%, both time spent in the kernel and total execution time
went up (8% and 4% respectively) compared to my original (and from
all I can tell worse) version of the patch. Nothing else changed as far as
I'm aware.
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
<Prev in Thread] Current Thread [Next in Thread>
Previous by Date: Re: [Xen-devel] [PATCH][TOOLS] ioemu: linking fix for *BSD , Christoph Egger
Next by Date: [Xen-devel] Re: ioemu-remote: USB Mouse/Tablet Doesn't Work , Ian Jackson
Previous by Thread: Re: [Xen-devel] Xen spinlock questions , Keir Fraser
Next by Thread: Re: [Xen-devel] Xen spinlock questions , Keir Fraser
Indexes: [Date] [Thread] [Top] [All Lists]

Copyright ©, Citrix Systems Inc. All rights reserved. Legal and Privacy
Citrix This site is hosted by Citrix

AltStyle によって変換されたページ (->オリジナル) /