Re: [libvirt] getFreeMemory reporting incorrectly?

On Thu, Jun 11, 2009 at 02:13:17PM -0400, Hany Fahim wrote: > My apologies. Here it is: > Xen 3.3: > > [root@node1 ~]# xm info > total_memory : 3063 > free_memory : 128 > node_to_cpu : node0:0-1 > node_to_memory : node0:128 > xen_major : 3 > xen_minor : 3 > xen_extra : .1 > > Xen 3.0.3: > > [root@node2 ~]# xm info > total_memory : 2046 > free_memory : 256 > node_to_cpu : node0:0 > xen_major : 3 > xen_minor : 1 > xen_extra : .2-128.1.6.el5 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. Regards, 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 :|