Re: [libvirt] [PATCH 4/4] Fix handling of sparse NUMA topologies

When finding a sparse NUMA topology, libnuma will return ENOENT the first time it is invoked. On subsequent invocations it will return success, but with an all-1's CPU mask. Check for this, to avoid polluting the capabilities XML with 4096 bogus CPUs * src/nodeinfo.c: Check for all-1s CPU mask --- src/nodeinfo.c | 14 +++++++++++++- 1 files changed, 13 insertions(+), 1 deletions(-) diff --git a/src/nodeinfo.c b/src/nodeinfo.c index 57db085..65eeb24 100644 --- a/src/nodeinfo.c +++ b/src/nodeinfo.c @@ -361,6 +361,7 @@ nodeCapsInitNUMA(virCapsPtr caps) { int n; unsigned long *mask = NULL; + unsigned long *allonesmask = NULL; int *cpus = NULL; int ret = -1; int max_n_cpus = NUMA_MAX_N_CPUS; @@ -371,13 +372,23 @@ nodeCapsInitNUMA(virCapsPtr caps) int mask_n_bytes = max_n_cpus / 8; if (VIR_ALLOC_N(mask, mask_n_bytes / sizeof *mask) < 0) goto cleanup; + if (VIR_ALLOC_N(allonesmask, mask_n_bytes / sizeof *mask) < 0) + goto cleanup; + memset(allonesmask, 0xff, mask_n_bytes); for (n = 0 ; n <= numa_max_node() ; n++) { int i; int ncpus; + /* The first time this returns -1, ENOENT if node doesn't exist... */ if (numa_node_to_cpus(n, mask, mask_n_bytes) < 0) { VIR_WARN("NUMA topology for cell %d of %d not available, ignoring", - n, numa_max_node()); + n, numa_max_node()+1); + continue; + } + /* second, third... times it returns an all-1's mask */ + if (memcmp(mask, allonesmask, mask_n_bytes) == 0) { + VIR_DEBUG("NUMA topology for cell %d of %d is all ones, ignoring", + n, numa_max_node()+1); continue; }

@@ -406,6 +417,7 @@ nodeCapsInitNUMA(virCapsPtr caps) cleanup: VIR_FREE(cpus); VIR_FREE(mask); + VIR_FREE(allonesmask); return ret; }