From f3ef78d4ce33b30b4231101b24bb74db2669537e Mon Sep 17 00:00:00 2001 From: Darrio Faggioli Date: Fri, 11 May 2012 12:39:43 +0100 Subject: [PATCH] libxl: use xc_topologyinfo to figure out how many CPUs we actually have Within libxl_get_cpu_topology(), considering all the CPUs the hypervisor supports to be valid topology entries might lead to misleading and incorrect behaviours, e.g., the output of `xl info -n' below on a 16 cores machine: ... cpu_topology : cpu: core socket node 0: 0 1 0 1: 0 1 0 2: 1 1 0 3: 1 1 0 4: 9 1 0 5: 9 1 0 6: 10 1 0 7: 10 1 0 8: 0 0 1 9: 0 0 1 10: 1 0 1 11: 1 0 1 12: 9 0 1 13: 9 0 1 14: 10 0 1 15: 10 0 1 16: 0 0 0 17: 0 0 0 18: 0 0 0 19: 0 0 0 20: 0 0 0 ... ... 62: 0 0 0 63: 0 0 0 However, xc_topologyinfo() tells us (in max_cpu_index) how many entries arrays it returns corresponds to actually valid CPUs, so let's use that information. Signed-off-by: Dario Faggioli Committed-by: Ian Jackson --- tools/libxl/libxl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index e641ad932a..14791d6e81 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -2897,6 +2897,9 @@ libxl_cputopology *libxl_get_cpu_topology(libxl_ctx *ctx, int *nr) goto fail; } + if (tinfo.max_cpu_index < max_cpus - 1) + max_cpus = tinfo.max_cpu_index + 1; + ret = malloc(sizeof(libxl_cputopology) * max_cpus); if (ret == NULL) { LIBXL__LOG_ERRNOVAL(ctx, XTL_ERROR, ENOMEM, -- 2.39.5