Re: [libvirt] [PATCH] conf: Check for NUMA distances in validity check
On 02/06/2018 09:34 PM, Peter Krempa wrote:
On Tue, Feb 06, 2018 at 17:23:47 +0100, Michal Privoznik wrote:
> NUMA distances are part of guest ABI (guests can read it
> directly!) and therefore as such shouldn't change throughout the
> lifetime of domain.
>
> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
> ---
> src/conf/numa_conf.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/src/conf/numa_conf.c b/src/conf/numa_conf.c
> index c906a53de..7d3f9e661 100644
> --- a/src/conf/numa_conf.c
> +++ b/src/conf/numa_conf.c
> @@ -1073,7 +1073,7 @@ bool
> virDomainNumaCheckABIStability(virDomainNumaPtr src,
> virDomainNumaPtr tgt)
> {
> - size_t i;
> + size_t i, j;
Please declare j on a separate line.
Okay.
> if (virDomainNumaGetNodeCount(src) != virDomainNumaGetNodeCount(tgt)) {
> virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> @@ -1102,6 +1102,17 @@ virDomainNumaCheckABIStability(virDomainNumaPtr src,
> "match source"), i);
> return false;
> }
> +
> + for (j = 0; j < virDomainNumaGetNodeCount(src); j++) {
Since the matrix of distances is symetrical along the diagonal, do we
really need to check both parts? As in .. how about initializing 'j' to
'i' in this loop?
Is it symmetrical? Does it have to be? I mean, I've never seen
asymmetrical NUMA machine but I don't usually bother checking distance
matrix when I'm on a NUMA machine (very rarely actually).
Michal