* Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
[not found] <1582654680.152201253087647836.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
@ 2009-09-16 7:56 ` Miroslav Rezanina
2009-09-16 13:24 ` [Xen-devel] " Konrad Rzeszutek Wilk
0 siblings, 1 reply; 7+ messages in thread
From: Miroslav Rezanina @ 2009-09-16 7:56 UTC (permalink / raw)
To: Jeremy Fitzhardinge; +Cc: linux-kernel, xen-devel
> From: "Jeremy Fitzhardinge" <jeremy@goop.org>
> To: "Miroslav Rezanina" <mrezanin@redhat.com>
> Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com
> Sent: Friday, September 4, 2009 1:26:24 AM GMT +01:00 Amsterdam / Berlin / Bern / Rome / Stockholm / Vienna
> Subject: Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
>
> On 08/19/09 06:05, Miroslav Rezanina wrote:
> > when running linux as XEN guest and use boot parameter mem= to set
> memory lower then is assigned to guest, not used memory should be
> returned to hypervisor as free. This is working with kernel available
> on xen.org pages, but is not working with kernel 2.6.29. Comparing
> both kernels I found code for returning unused memory to hypervisor is
> missing. Following patch add this functionality to 2.6.29 kernel.
> >
>
> Are you planning on submitting a revised patch along the lines I
> suggested?
>
> Thanks,
> J
General version of patch. This version checks the e820 map for holes
and returns all memory that is not mapped.
Patch:
===========
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index b58e963..acc9166 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -31,6 +31,7 @@
#include <xen/interface/version.h>
#include <xen/interface/physdev.h>
#include <xen/interface/vcpu.h>
+#include <xen/interface/memory.h>
#include <xen/features.h>
#include <xen/page.h>
#include <xen/hvc-console.h>
@@ -122,6 +123,59 @@ static int have_vcpu_info_placement =
#endif
;
+void __init xen_return_unused_memory(void)
+{
+ static struct e820map holes = {
+ .nr_map = 0
+ };
+ struct xen_memory_reservation reservation = {
+ .address_bits = 0,
+ .extent_order = 0,
+ .domid = DOMID_SELF
+ };
+ unsigned long last_end = 0;
+ int i;
+
+ for(i=0;i<e820.nr_map;i++) {
+ if (e820.map[i].addr > last_end) {
+ holes.map[holes.nr_map].addr = last_end;
+ holes.map[holes.nr_map].size =
+ e820.map[i].addr - last_end;
+ holes.nr_map++;
+ }
+ last_end = e820.map[i].addr + e820.map[i].size;
+ }
+
+ if (last_end < PFN_PHYS((u64)xen_start_info->nr_pages)) {
+ holes.map[holes.nr_map].addr=last_end;
+ holes.map[holes.nr_map].size =
+ PFN_PHYS((u64)xen_start_info->nr_pages) - last_end;
+ holes.nr_map++;
+ }
+
+ if (holes.nr_map == 0)
+ return;
+
+ for(i=0;i<holes.nr_map;i++) {
+ unsigned long spfn = holes.map[i].addr >> PAGE_SHIFT;
+ unsigned long epfn = ((holes.map[i].addr + holes.map[i].size) >> PAGE_SHIFT);
+ int ret;
+
+ if (spfn % PAGE_SIZE != 0)
+ spfn++;
+
+ if (spfn >= epfn)
+ continue;
+
+ set_xen_guest_handle(reservation.extent_start,
+ ((unsigned long *)xen_start_info->mfn_list) + spfn);
+
+ reservation.nr_extents = epfn - spfn;
+ ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
+ &reservation);
+ BUG_ON (ret != epfn - spfn);
+ }
+}
static void xen_vcpu_setup(int cpu)
{
@@ -1057,6 +1111,8 @@ static __init void xen_post_allocator_init(void)
SetPagePinned(virt_to_page(level3_user_vsyscall));
#endif
xen_mark_init_mm_pinned();
+
+/* xen_return_unused_memory(); */
}
/* This is called once we have the cpu_possible_map */
--
Miroslav Rezanina
Software Engineer - Virtualization Team - XEN kernel
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
2009-09-16 7:56 ` [PATCH][v2.6.29][XEN] Return unused memory to hypervisor Miroslav Rezanina
@ 2009-09-16 13:24 ` Konrad Rzeszutek Wilk
0 siblings, 0 replies; 7+ messages in thread
From: Konrad Rzeszutek Wilk @ 2009-09-16 13:24 UTC (permalink / raw)
To: Miroslav Rezanina; +Cc: Jeremy Fitzhardinge, xen-devel, linux-kernel
. snip ..
> static void xen_vcpu_setup(int cpu)
> {
> @@ -1057,6 +1111,8 @@ static __init void xen_post_allocator_init(void)
> SetPagePinned(virt_to_page(level3_user_vsyscall));
> #endif
> xen_mark_init_mm_pinned();
> +
> +/* xen_return_unused_memory(); */
Should this be commented out? Or do you plan to provide another
patch to enable this after extensive testing?
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
[not found] <625566043.266451253249879910.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
@ 2009-09-18 5:02 ` Miroslav Rezanina
0 siblings, 0 replies; 7+ messages in thread
From: Miroslav Rezanina @ 2009-09-18 5:02 UTC (permalink / raw)
To: Jeremy Fitzhardinge; +Cc: xen-devel, linux-kernel, Konrad Rzeszutek Wilk
----- "Jeremy Fitzhardinge" <jeremy@goop.org> wrote:
> From: "Jeremy Fitzhardinge" <jeremy@goop.org>
> To: "Miroslav Rezanina" <mrezanin@redhat.com>
> Cc: xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, "Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>
> Sent: Thursday, September 17, 2009 6:47:10 PM GMT +01:00 Amsterdam / Berlin / Bern / Rome / Stockholm / Vienna
> Subject: Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
>
> On 09/17/09 01:14, Miroslav Rezanina wrote:
> > Hi Jeremy,
> > I check your application. It won't work correctly. You are calling
> return_unused_memory in xen_memory_setup that is too soon.
> > When you are calling it, there is no hole in map in any case.
> Calling should be in xen_post_allocator_init function (in
> arch/x86/xen/mmu.c).
> >
>
> OK. Where does the e820 map get changed in the meantime?
>
xen_memory_setup just set RAM map from 0 to initial nr_pages. Only one place I'm sure map is changed is
parsing mem parameter. You mentioned that there can be other cases when some parts of map are removed.
> J
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
--
Miroslav Rezanina
Software Engineer - Virtualization Team - XEN kernel
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
2009-09-17 8:14 ` Miroslav Rezanina
@ 2009-09-17 16:47 ` Jeremy Fitzhardinge
0 siblings, 0 replies; 7+ messages in thread
From: Jeremy Fitzhardinge @ 2009-09-17 16:47 UTC (permalink / raw)
To: Miroslav Rezanina; +Cc: Konrad Rzeszutek Wilk, xen-devel, linux-kernel
On 09/17/09 01:14, Miroslav Rezanina wrote:
> Hi Jeremy,
> I check your application. It won't work correctly. You are calling return_unused_memory in xen_memory_setup that is too soon.
> When you are calling it, there is no hole in map in any case. Calling should be in xen_post_allocator_init function (in arch/x86/xen/mmu.c).
>
OK. Where does the e820 map get changed in the meantime?
J
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
[not found] <976992170.207631253175200763.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
@ 2009-09-17 8:14 ` Miroslav Rezanina
2009-09-17 16:47 ` Jeremy Fitzhardinge
0 siblings, 1 reply; 7+ messages in thread
From: Miroslav Rezanina @ 2009-09-17 8:14 UTC (permalink / raw)
To: Jeremy Fitzhardinge; +Cc: Konrad Rzeszutek Wilk, xen-devel, linux-kernel
Hi Jeremy,
I check your application. It won't work correctly. You are calling return_unused_memory in xen_memory_setup that is too soon.
When you are calling it, there is no hole in map in any case. Calling should be in xen_post_allocator_init function (in arch/x86/xen/mmu.c).
Mirek
----- "Jeremy Fitzhardinge" <jeremy@goop.org> wrote:
> From: "Jeremy Fitzhardinge" <jeremy@goop.org>
> To: "Miroslav Rezanina" <mrezanin@redhat.com>
> Cc: "Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org
> Sent: Thursday, September 17, 2009 6:54:56 AM GMT +01:00 Amsterdam / Berlin / Bern / Rome / Stockholm / Vienna
> Subject: Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
>
> On 09/16/09 21:43, Miroslav Rezanina wrote:
> > Ups.....This should not be commented out. I will resent the patch
> with
> > correct (uncommented) line.
>
> I've already applied a variant of your patch. Check the
> rebase/core-freemem branch in xen.git.
>
> J
>
> --
> To unsubscribe from this list: send the line "unsubscribe
> linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
Miroslav Rezanina
Software Engineer - Virtualization Team - XEN kernel
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
2009-09-17 4:43 ` Miroslav Rezanina
@ 2009-09-17 4:54 ` Jeremy Fitzhardinge
0 siblings, 0 replies; 7+ messages in thread
From: Jeremy Fitzhardinge @ 2009-09-17 4:54 UTC (permalink / raw)
To: Miroslav Rezanina; +Cc: Konrad Rzeszutek Wilk, xen-devel, linux-kernel
On 09/16/09 21:43, Miroslav Rezanina wrote:
> Ups.....This should not be commented out. I will resent the patch with
> correct (uncommented) line.
I've already applied a variant of your patch. Check the
rebase/core-freemem branch in xen.git.
J
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
[not found] <1772017457.205391253162074470.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
@ 2009-09-17 4:43 ` Miroslav Rezanina
2009-09-17 4:54 ` Jeremy Fitzhardinge
0 siblings, 1 reply; 7+ messages in thread
From: Miroslav Rezanina @ 2009-09-17 4:43 UTC (permalink / raw)
To: Konrad Rzeszutek Wilk; +Cc: Jeremy Fitzhardinge, xen-devel, linux-kernel
----- "Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com> wrote:
> From: "Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>
> To: "Miroslav Rezanina" <mrezanin@redhat.com>
> Cc: "Jeremy Fitzhardinge" <jeremy@goop.org>, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org
> Sent: Wednesday, September 16, 2009 3:24:56 PM GMT +01:00 Amsterdam / Berlin / Bern / Rome / Stockholm / Vienna
> Subject: Re: [Xen-devel] Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor
>
> . snip ..
> > static void xen_vcpu_setup(int cpu)
> > {
> > @@ -1057,6 +1111,8 @@ static __init void
> xen_post_allocator_init(void)
> > SetPagePinned(virt_to_page(level3_user_vsyscall));
> > #endif
> > xen_mark_init_mm_pinned();
> > +
> > +/* xen_return_unused_memory(); */
>
> Should this be commented out? Or do you plan to provide another
> patch to enable this after extensive testing?
>
Ups.....This should not be commented out. I will resent the patch with
correct (uncommented) line.
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
--
Miroslav Rezanina
Software Engineer - Virtualization Team - XEN kernel
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2009-09-18 5:02 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <1582654680.152201253087647836.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2009-09-16 7:56 ` [PATCH][v2.6.29][XEN] Return unused memory to hypervisor Miroslav Rezanina
2009-09-16 13:24 ` [Xen-devel] " Konrad Rzeszutek Wilk
[not found] <1772017457.205391253162074470.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2009-09-17 4:43 ` Miroslav Rezanina
2009-09-17 4:54 ` Jeremy Fitzhardinge
[not found] <976992170.207631253175200763.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2009-09-17 8:14 ` Miroslav Rezanina
2009-09-17 16:47 ` Jeremy Fitzhardinge
[not found] <625566043.266451253249879910.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com>
2009-09-18 5:02 ` Miroslav Rezanina
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.