|
|
|
|
|
|
|
|
|
|
xen-devel
[Xen-devel] Re: [PATCH V4] mm: Extend memory hotplug API to allow memory
To: |
Daniel Kiper <dkiper@xxxxxxxxxxxx> |
Subject: |
[Xen-devel] Re: [PATCH V4] mm: Extend memory hotplug API to allow memory hotplug in virtual machines |
From: |
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> |
Date: |
Thu, 2 Jun 2011 12:26:07 -0700 |
Cc: |
jeremy@xxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxx, ian.campbell@xxxxxxxxxx, haicheng.li@xxxxxxxxxxxxxxx, konrad.wilk@xxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, dan.magenheimer@xxxxxxxxxx, v.tolstov@xxxxxxxxx, dave@xxxxxxxxxxxxxxxxxx, linux-mm@xxxxxxxxx, rientjes@xxxxxxxxxx, fengguang.wu@xxxxxxxxx, wdauchy@xxxxxxxxx |
Delivery-date: |
Thu, 02 Jun 2011 12:27:24 -0700 |
Envelope-to: |
www-data@xxxxxxxxxxxxxxxxxxx |
In-reply-to: |
<20110524222733.GA29133@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> |
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: |
<20110524222733.GA29133@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> |
Sender: |
xen-devel-bounces@xxxxxxxxxxxxxxxxxxx |
On Wed, 25 May 2011 00:27:33 +0200
Daniel Kiper <dkiper@xxxxxxxxxxxx> wrote:
> This patch applies to Linus' git tree, git commit
> 98b98d316349e9a028e632629fe813d07fa5afdd
> (Merge branch 'drm-core-next' of
> git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6)
> with a few prerequisite patches available at
> https://lkml.org/lkml/2011/5/2/296
> and https://lkml.org/lkml/2011/5/17/408 (all prerequisite patches were
> included in -mm tree).
>
> This patch contains online_page_callback and apropriate functions for
> registering/unregistering online page callbacks. It allows to do some
> machine specific tasks during online page stage which is required
> to implement memory hotplug in virtual machines. Currently this patch
> is required by latest memory hotplug support for Xen balloon driver
> patch which will be posted soon.
>
> Additionally, originial online_page() function was splited into
> following functions doing "atomic" operations:
> - __online_page_set_limits() - set new limits for memory management code,
> - __online_page_increment_counters() - increment totalram_pages and
> totalhigh_pages,
> - __online_page_free() - free page to allocator.
>
> It was done to:
> - not duplicate existing code,
> - ease hotplug code devolpment by usage of well defined interface,
> - avoid stupid bugs which are unavoidable when the same code
> (by design) is developed in many places.
I grabbed this and the xen patch. I assume that all prerequisites
are now in mainline?
Please give some thought to making this extra code Kconfigurable, and
selected by Xen? See if we can avoid a bit of bloat for other kernel
users.
What is missing from the patchset is an explanation of why we should
merge it ;) Why is this feature desirable? What value does it provide
to our users? Why should we bother? Answering these questions in a
form which can be pasted into the changelog would be convenient,
thanks.
Is there any propsect that the other virtualisation schemes will use
this facility? If not, why not?
>
> ...
>
> @@ -388,7 +450,7 @@ static int online_pages_range(unsigned long start_pfn,
> unsigned long nr_pages,
> if (PageReserved(pfn_to_page(start_pfn)))
> for (i = 0; i < nr_pages; i++) {
> page = pfn_to_page(start_pfn + i);
> - online_page(page);
> + online_page_callback(page);
nit. I'll change this to
(*online_page_callback)(page);
because that syntax communicates some useful information to the reader.
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
<Prev in Thread] |
Current Thread |
[Next in Thread>
|
- [Xen-devel] Re: [PATCH V4] mm: Extend memory hotplug API to allow memory hotplug in virtual machines,
Andrew Morton <=
|
|
|
|
|