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] is paging_new_log_dirty_page alloc page harmfull?

To: <tim.deegan@xxxxxxxxxx>
Subject: RE: [Xen-devel] is paging_new_log_dirty_page alloc page harmfull?
From: MaoXiaoyun <tinnycloud@xxxxxxxxxxx>
Date: Mon, 7 Mar 2011 11:41:56 +0800
Cc: xen devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Sun, 06 Mar 2011 19:42:32 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
Importance: Normal
In-reply-to: <20110304111659.GA23341@xxxxxxxxxxxxxxxxxxxxxxx>
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: <BLU157-w46D6341FE9D3E2BE2DBB33DAC20@xxxxxxx>, <20110304111659.GA23341@xxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thanks Tim.
Do you have suggestion on how many memory I should reserved, is 512M enough?
 
There is a balloon daemon process in dom0 do the memory management, the striaght
way to reserve memory is after recycle memory form domains which no need memory
, then give the memory to those domains who need memory. What do you think of this?
 
> Date: Fri, 4 Mar 2011 11:16:59 +0000
> From: Tim.Deegan@xxxxxxxxxx
> To: tinnycloud@xxxxxxxxxxx
> CC: xen-devel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-devel] is paging_new_log_dirty_page alloc page harmfull?
>
> At 11:11 +0000 on 04 Mar (1299237101), MaoXiaoyun wrote:
> > Hi:
> >
> > I've been testing on memory overcommit on Xen by using balloon driver.
> > On our stress test, it is possilbe that heap memory in xen is use up. Thus the serial
> > port will show log as below:
> >
> > (XEN) paging_log_dirty_range: 138 failed page allocs while logging dirty pages
> > (XEN) paging_log_dirty_range: 138 failed page allocs while logging dirty pages
> > (XEN) paging_log_dirty_range: 138 failed page allocs while logging dirty pages
> >
> > I am asking is it harmfull to domain?
>
> It means that the log-dirty code wasn't able to ex tend its bitmap and
> callers have to assume that all pages are dirty. It's bad for
> performance but should be OK.
>
> If you rebase to the latest 4.1 RC, this particular message should go
> away as log-dirty bitmaps are no longer pulled from common memory.
>
> > If so, I might need find a way to reserve some memory for xen, which looks
> > kinds of difficult.
>
> I think you might find you need to do this anyway - there are other
> dynamic allocations in Xen which might not fail so gracefully (in
> particular around setting up new domains).
>
> Tim.
>
> --
> Tim Deegan <Tim.Deegan@xxxxxxxxxx>
> Principal Software Engineer, Xen Platform Team
> Citrix Systems UK Ltd. (Company #02937203, SL9 0BG)
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel