[libvirt] getFreeMemory reporting incorrectly?
Hany Fahim
hany.fahim at gmail.com
Fri Jun 12 17:51:24 UTC 2009
Hey Daniel,
I just patched the source and compiled. It properly reports the free memory
now:
[root at node1 ~]# python
Python 2.4.3 (#1, Jan 21 2009, 01:10:13)
[GCC 4.1.2 20071124 (Red Hat 4.1.2-42)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import libvirt
>>> conn = libvirt.open('xen:///')
>>> print(conn.getFreeMemory())
134217728
Thanks for all your help!
Hany
On Fri, Jun 12, 2009 at 10:44 AM, Daniel P. Berrange <berrange at redhat.com>wrote:
> On Thu, Jun 11, 2009 at 02:37:57PM -0400, Hany Fahim wrote:
> > Thanks Daniel,
> > Is it fair to assume this fix may appear in the next release of libvirt?
>
> If you want to build from source, I'd appreciate feedback on whether
> the following patch fixes the problem
>
> diff -r f204769dd197 src/xen_internal.c
> --- a/src/xen_internal.c Wed Jun 03 13:52:06 2009 +0000
> +++ b/src/xen_internal.c Fri Jun 12 15:44:05 2009 +0100
> @@ -241,6 +241,15 @@ struct xen_v2s4_availheap {
>
> typedef struct xen_v2s4_availheap xen_v2s4_availheap;
>
> +struct xen_v2s5_availheap {
> + uint32_t min_bitwidth; /* Smallest address width (zero if don't
> care). */
> + uint32_t max_bitwidth; /* Largest address width (zero if don't care).
> */
> + int32_t node; /* NUMA node (-1 for sum across all nodes). */
> + uint64_t avail_bytes ALIGN_64; /* Bytes available in the specified
> region. */
> +};
> +
> +typedef struct xen_v2s5_availheap xen_v2s5_availheap;
> +
>
> #define XEN_GETDOMAININFOLIST_ALLOC(domlist, size) \
> (hypervisor_version < 2 ? \
> @@ -650,6 +659,7 @@ struct xen_op_v2_sys {
> xen_v2s3_getdomaininfolistop getdomaininfolists3;
> xen_v2_getschedulerid getschedulerid;
> xen_v2s4_availheap availheap;
> + xen_v2s5_availheap availheap5;
> uint8_t padding[128];
> } u;
> };
> @@ -3125,12 +3135,18 @@ xenHypervisorNodeGetCellsFreeMemory(virC
> op_sys.cmd = XEN_V2_OP_GETAVAILHEAP;
>
> for (i = startCell, j = 0;(i < priv->nbNodeCells) && (j <
> maxCells);i++,j++) {
> - op_sys.u.availheap.node = i;
> + if (sys_interface_version >= 5)
> + op_sys.u.availheap5.node = i;
> + else
> + op_sys.u.availheap.node = i;
> ret = xenHypervisorDoV2Sys(priv->handle, &op_sys);
> if (ret < 0) {
> return(-1);
> }
> - freeMems[j] = op_sys.u.availheap.avail_bytes;
> + if (sys_interface_version >= 5)
> + freeMems[j] = op_sys.u.availheap5.avail_bytes;
> + else
> + freeMems[j] = op_sys.u.availheap.avail_bytes;
> }
> return (j);
> }
>
>
>
> > >
> > >
> > > This shows that the Hypervisor is giving correct info back with both
> > > versions. So the problem must be at the libvirt space, and I believe
> > > I know what the problem is.
> > >
> > > The version of Xen in RHEL5 has
> > >
> > > struct xen_sysctl_availheap {
> > > /* IN variables. */
> > > uint32_t min_bitwidth; /* Smallest address width (zero if don't
> care).
> > > */
> > > uint32_t max_bitwidth; /* Largest address width (zero if don't
> care).
> > > */
> > > int32_t node; /* NUMA node of interest (-1 for all nodes).
> */
> > > /* OUT variables. */
> > > uint64_t avail_bytes; /* Bytes available in the specified region.
> */
> > > };
> > >
> > > While upstream Xen has
> > >
> > > struct xen_sysctl_availheap {
> > > /* IN variables. */
> > > uint32_t min_bitwidth; /* Smallest address width (zero if don't
> care).
> > > */
> > > uint32_t max_bitwidth; /* Largest address width (zero if don't
> care).
> > > */
> > > int32_t node; /* NUMA node of interest (-1 for all nodes).
> */
> > > /* OUT variables. */
> > > uint64_aligned_t avail_bytes;/* Bytes available in the specified
> region.
> > > */
> > > };
> > >
> > > Notice the 'avail_bytes' field is now aligned, so its 4 bytes further
> > > down from where libvirt is expecting it to be.
> > >
> > > We'll have to provide a fix in libvirt to use the new alignment for
> > > newer Xen.
>
> Daniel
> --
> |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/:|
> |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org:|
> |: http://autobuild.org -o- http://search.cpan.org/~danberr/:|
> |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505
> :|
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20090612/cb17c44f/attachment-0001.htm>
More information about the libvir-list
mailing list