* Ryan Harper <ryanh@xxxxxxxxxx> [2006-07-31 14:13]:
> >From [1]previous post:
> > This patch modifies three memory operations to be NUMA-aware:
> >
> > increase_reservation
> > populate_physmap
> > memory_exchange
> >
> > These three operations request memory from the domain heap and have been
> > modified to distribute the request across the physical cpus of the
> > target domain evenly. This make memory local to the physical cpus
> > within the domain available for the guest.
>
> Measuring the overhead has shown the distribution to be costly with at
> the current time, no specific benefit since the best case would be
> providing local memory in a multi-node guest environment. As we
> currently don't export this virtual domain topology to Linux, it can't
> take advantage of the local allocations. At this time, most domains
> created on NUMA machines will modify their config file parameters to
> ensure they fit within a single NUMA node and render the distribution
> code useless. This patch removes the extra logic and uses domain's vcpu
> 0 processor as the parameter into the heap allocation function.
>
> Now domains will use VCPU0 to pick which node to allocate memory from
> (using cpu_to_node mapping) and we don't pay for logic that won't be
> leveraged.
>
>
> [1] http://lists.xensource.com/archives/html/xen-devel/2006-07/msg00544.html
-no changes
--
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
(512) 838-9253 T/L: 678-9253
ryanh@xxxxxxxxxx
diffstat output:
memory.c | 21 ++++++++++++++-------
1 files changed, 14 insertions(+), 7 deletions(-)
Signed-off-by: Ryan Harper <ryanh@xxxxxxxxxx>
---
Make memory hypercalls NUMA-aware
diff -r fa87cea10778 xen/common/memory.c
--- a/xen/common/memory.c Tue Aug 15 11:38:13 2006 -0500
+++ b/xen/common/memory.c Tue Aug 15 11:40:17 2006 -0500
@@ -40,6 +40,8 @@ increase_reservation(
struct page_info *page;
unsigned long i;
xen_pfn_t mfn;
+ /* use domain's first processor for locality parameter */
+ unsigned int cpu = d->vcpu[0]->processor;
if ( !guest_handle_is_null(extent_list) &&
!guest_handle_okay(extent_list, nr_extents) )
@@ -57,8 +59,8 @@ increase_reservation(
return i;
}
- if ( unlikely((page = alloc_domheap_pages(
- d, extent_order, memflags)) == NULL) )
+ if ( unlikely((page = __alloc_domheap_pages( d, cpu,
+ extent_order, memflags )) == NULL) )
{
DPRINTK("Could not allocate order=%d extent: "
"id=%d memflags=%x (%ld of %d)\n",
@@ -91,6 +93,8 @@ populate_physmap(
unsigned long i, j;
xen_pfn_t gpfn;
xen_pfn_t mfn;
+ /* use domain's first processor for locality parameter */
+ unsigned int cpu = d->vcpu[0]->processor;
if ( !guest_handle_okay(extent_list, nr_extents) )
return 0;
@@ -110,8 +114,8 @@ populate_physmap(
if ( unlikely(__copy_from_guest_offset(&gpfn, extent_list, i, 1)) )
goto out;
- if ( unlikely((page = alloc_domheap_pages(
- d, extent_order, memflags)) == NULL) )
+ if ( unlikely((page = __alloc_domheap_pages( d, cpu,
+ extent_order, memflags )) == NULL) )
{
DPRINTK("Could not allocate order=%d extent: "
"id=%d memflags=%x (%ld of %d)\n",
@@ -293,7 +297,7 @@ memory_exchange(XEN_GUEST_HANDLE(xen_mem
unsigned long in_chunk_order, out_chunk_order;
xen_pfn_t gpfn, gmfn, mfn;
unsigned long i, j, k;
- unsigned int memflags = 0;
+ unsigned int memflags = 0, cpu;
long rc = 0;
struct domain *d;
struct page_info *page;
@@ -367,6 +371,9 @@ memory_exchange(XEN_GUEST_HANDLE(xen_mem
}
d = current->domain;
+ /* use domain's first processor for locality parameter */
+ cpu = d->vcpu[0]->processor;
+
for ( i = 0; i < (exch.in.nr_extents >> in_chunk_order); i++ )
{
if ( hypercall_preempt_check() )
@@ -412,8 +419,8 @@ memory_exchange(XEN_GUEST_HANDLE(xen_mem
/* Allocate a chunk's worth of anonymous output pages. */
for ( j = 0; j < (1UL << out_chunk_order); j++ )
{
- page = alloc_domheap_pages(
- NULL, exch.out.extent_order, memflags);
+ page = __alloc_domheap_pages( NULL, cpu,
+ exch.out.extent_order, memflags);
if ( unlikely(page == NULL) )
{
rc = -ENOMEM;
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