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/
Home Products Support Community News


Re: [Xen-devel] [PATCH 2 of 8] libxl: introduce libxl_set_relative_memor

To: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH 2 of 8] libxl: introduce libxl_set_relative_memory_target
From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Date: Wed, 1 Sep 2010 11:55:46 +0100
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Stefano Stabellini <Stefano.Stabellini@xxxxxxxxxxxxx>
Delivery-date: Wed, 01 Sep 2010 03:56:50 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <19581.15132.637644.952724@xxxxxxxxxxxxxxxxxxxxxxxx>
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: <alpine.DEB.2.00.1008271215210.2545@kaball-desktop> <19581.15132.637644.952724@xxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Alpine 2.00 (DEB 1167 2008-08-23)
On Tue, 31 Aug 2010, Ian Jackson wrote:
> Stefano Stabellini writes ("[Xen-devel] [PATCH 2 of 8] libxl: introduce 
> libxl_set_relative_memory_target"):
> > libxl: introduce libxl_set_relative_memory_target
> > 
> > Introduce libxl_set_relative_memory_target to modify the memory target
> > of a domain by a relative amount of memory in a single xenstore
> > transaction.
> > Modify libxl_set_memory_target to use xenstore transactions.
> > The first time we are reading/writing dom0 memory target, fill the
> > informations in xenstore if they are missing.
> >  int libxl_set_memory_target(libxl_ctx *ctx, uint32_t domid,
> >                              uint32_t target_memkb, int enforce)
> See my earlier comments about memory targets.  I don't think it makes
> much sense to give a domain a memory target and then let it exceed it.
> So I think "enforce" should be abolished (as if it were always set).

I can do that.

> Also please can you try to keep your code to <75ish columns ? :-)
> (75 because there should be room for > and + quoting without wrap
> damage.)

Yes. We need a CODING_STILE, I'll post a patch with it later on.

> >  int libxl_set_memory_target(libxl_ctx *ctx, uint32_t domid,
> >                 uint32_t target_memkb, int enforce)
> ...
> > +int libxl_set_relative_memory_target(libxl_ctx *ctx, uint32_t
> > +            domid, int32_t relative_target_memkb, int enforce)
> These functions are really rather too similar for my taste.  They
> seem to differ only in whether they read the existing target and add
> it on.  Surely they should be combined.
> Also, I don't really think this patch to introuce the relative setting
> function should involves adding a lot of code to the absolute setting
> function.  It's a shame that we have to set so many different copies
> of the same value, but if we do then that should be done in a separate
> patch first perhaps ?

The separate patch is a good idea, but merging the two functions
together will result in code harder to read in the implementation of a
very important function.

Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • Re: [Xen-devel] [PATCH 2 of 8] libxl: introduce libxl_set_relative_memory_target, Stefano Stabellini <=