tools/power turbostat: fix bogus summary values
This patch fixes a regression introduced in commit 8cb48b32 ("tools/power turbostat: track thread ID in cpu_topology") Turbostat uses incorrect cores number ('topo.num_cores') - its value is count of logical CPUs, instead of count of physical cores. So it is twice as large as it should be on a typical Intel system. For example, on a 6 core Xeon system 'topo.num_cores' is 12, and on a 52 core Xeon system 'topo.num_cores' is 104. And interestingly, on a 68-core Knights Landing Intel system 'topo.num_cores' is 272, because this system has 4 logical CPUs per core. As a result, some of the turbostat calculations are incorrect. For example, on idle 52-core Xeon system when all cores are ~99% in Core C6 (CPU%c6), the summary (very first) line shows ~48% Core C6, while it should be ~99%. This patch fixes the problem by fixing 'topo.num_cores' calculation. Was: 1. Init 'thread_id' for all CPUs to -1 2. Run 'get_thread_siblings()' which sets it to 0 or 1 3. Increment 'topo.num_cores' when thread_id != -1 (bug!) Now: 1. Init 'thread_id' for all CPUs to -1 2. Run 'get_thread_siblings()' which sets it to 0 or 1 3. Increment 'topo.num_cores' when thread_id is not 0 I did not have a chance to test this on an AMD machine, and only tested on a couple of Intel Xeons (6 and 52 cores). Reported-by: Vladislav Govtva <vladislav.govtva@intel.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
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