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 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] [xen-unstable test] 6947: regressions - trouble: broken/

To: Jan Beulich <JBeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] [xen-unstable test] 6947: regressions - trouble: broken/fail/pass
From: Keir Fraser <keir.xen@xxxxxxxxx>
Date: Tue, 03 May 2011 15:09:10 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Tue, 03 May 2011 07:13:43 -0700
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:user-agent:date:subject:from:to:cc:message-id :thread-topic:thread-index:in-reply-to:mime-version:content-type :content-transfer-encoding; bh=1KvgQDrGNR+UtpLMsJVfMqUgyCyo0lqWB5gXfg498DM=; b=BJvicBJWOwmQnbWj7jvkJvQjq30WjFfeaO8OlDsfb4tQ+v0dtkMHIoiy4OAbEObtrq DZgJMoON+DyTY5YdtOMf+1m7+tc2kputlJRrri9YXjd+xyWG45ZLrkMIQGKmpn9Mu7nn Oh3/+2NIT3OaSrguH+1KM46mQQRnIUtl/7/xg=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=user-agent:date:subject:from:to:cc:message-id:thread-topic :thread-index:in-reply-to:mime-version:content-type :content-transfer-encoding; b=Imjhrjf8DAJiv23G9t4Mo2HTue0kY0K0E/0D02l441N3qHaI+bn55LXVxrSxtiFlof y+Oavrdypnc5Y/IfhVt25QOXDOffjtwDVBcSYRN9GRqjfJch/ouNOozjyFzLe7SUAPBr Yp1oxDW6v2bfLCgRMXVft9iM8Ll+1OV3MRpQw=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4DC02118020000780003F666@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>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcwJm6wry2BEwS9B6kGwZ/A2YJLqfw==
Thread-topic: [Xen-devel] [xen-unstable test] 6947: regressions - trouble: broken/fail/pass
User-agent: Microsoft-Entourage/12.29.0.110113
On 03/05/2011 14:36, "Jan Beulich" <JBeulich@xxxxxxxxxx> wrote:

>> But the readers in irq context will call lookup_slot() without d->event_lock
>> held? In that case you do need an RCU-aware version of radix-tree.[ch],
>> because lookups can be occurring concurrently with insertions/deletions.
> 
> No, in IRQ context we only need the irq -> pirq translation afaics, and
> that translation doesn't use an allocated object (it instead simply inserts
> the [non-zero] pirq as data item).

Ah well that makes things easier. :-) If a single lock protects all
operations (including lookups) on a particular radix tree then of course we
don't need RCU.

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel