On Tue, Jan 31, 2017 at 05:03:51PM +0100, Jan Stancek wrote: SNIP
> > There are 2 problems wrt. cpu_topology_map on systems with sparse CPUs: > > 1. offline/absent CPUs will have their socket_id and core_id set to -1 > which triggers: > "socket_id number is too big.You may need to upgrade the perf tool." > > 2. size of cpu_topology_map (perf_env.cpu[]) is allocated based on > _SC_NPROCESSORS_CONF, but can be indexed with CPU ids going above. > Users of perf_env.cpu[] are using CPU id as index. This can lead > to read beyond what was allocated: > ==19991== Invalid read of size 4 > ==19991== at 0x490CEB: check_cpu_topology (topology.c:69) > ==19991== by 0x490CEB: test_session_topology (topology.c:106) > ... > > For example: > _SC_NPROCESSORS_CONF == 16 > available: 2 nodes (0-1) > node 0 cpus: 0 6 8 10 16 22 24 26 > node 0 size: 12004 MB > node 0 free: 9470 MB > node 1 cpus: 1 7 9 11 23 25 27 > node 1 size: 12093 MB > node 1 free: 9406 MB > node distances: > node 0 1 > 0: 10 20 > 1: 20 10 so what's max_present_cpu in this example? jirka
