From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Egger, Christoph" <chegger@amazon.de>
Subject: Re: [PATCH v3 1/2] gnttab: Introduce rwlock to protect
 updates to grant table state
Date: Fri, 9 Jan 2015 14:05:13 +0100
Message-ID: <54AFD209.70209@amazon.de>
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To: Jan Beulich <JBeulich@suse.com>
Cc: Julien Grall <julien.grall@linaro.org>, Keir Fraser <keir@xen.org>, Matt Wilson <msw@amazon.com>, xen-devel@lists.xen.org
List-Id: xen-devel@lists.xenproject.org

On 2014/12/18 12:37, Jan Beulich wrote:
>>>> On 03.12.14 at 15:29, <chegger@amazon.de> wrote:
>> --- a/xen/common/grant_table.c
>> +++ b/xen/common/grant_table.c
[...]
>> @@ -944,6 +944,7 @@ __gnttab_unmap_common(
>>      }
>>  
>>      op->rd = rd;
>> +    read_lock(&rgt->lock);
>>      act = &active_entry(rgt, op->map->ref);
>>  
>>      if ( op->frame == 0 )
> 
> The nesting of the two locks should be mentioned in the doc change.

Where do you see the nesting coming from?

Christoph