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] [PATCH] Fix deadlock in schedule.c at TRACE mode

To: NISHIGUCHI Naoki <nisiguti@xxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] Fix deadlock in schedule.c at TRACE mode
From: Atsushi SAKAI <sakaia@xxxxxxxxxxxxxx>
Date: Thu, 24 Apr 2008 14:42:53 +0900
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Wed, 23 Apr 2008 22:43:35 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <48100DF2.5000605@xxxxxxxxxxxxxx>
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/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <48100DF2.5000605@xxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Hi, Naoki

I have two questions about this.

1)How to reproduce your deadlock ?
  Would you give me your test environment to reproduce this deadlock?
  Is it easily reproduced by running xenmon.py or xentrace 
  with one or two guest domain(s)?
 or Any additional condition needed?

2)About fixing code,
  I think __trace_var() should fix for this issue not schedule()
  This issue cannot be fixed by modify the __trace_var()?

Thanks
Atsushi SAKAI


NISHIGUCHI Naoki <nisiguti@xxxxxxxxxxxxxx> wrote:

> Hi,
> 
> In schedule.c, schedule() and sched_adjust() call trace functions during
> acquiring lock of schedule_lock in each cpu's schedule_data. When trace
> buffers are enabled, the trace function (__trace_var()) may call
> vcpu_wake() by calling send_guest_global_virq(). In the case, a deadlock
> occurs when acquiring lock of schedule_lock.
> 
> Attached patch fixes this problem.
> 
> Signed-off-by: Naoki Nishiguchi <nisiguti@xxxxxxxxxxxxxx>
> 
> Regards,
> Naoki Nishiguchi



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

<Prev in Thread] Current Thread [Next in Thread>