PPA: https://launchpad.net/~inaddy/+archive/ubuntu/lp1575407
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1575407 Title: Trusty + 3.19 (lts-vivid) PERF wrong cpu-migration counter Status in linux package in Ubuntu: Confirmed Bug description: It was brought to my attention that: In a PowerPC based server, PERF seems to acuse cpu-migrations when only a single cpu is activated. ## perf Performance counter stats for 'CPU(s) 0': 15027.888988 task-clock (msec) # 1.000 CPUs utilized [100.00%] 25,206 context-switches # 0.002 M/sec [100.00%] 3,518 cpu-migrations # 0.234 K/sec [100.00%] 639 page-faults # 0.043 K/sec 41,545,780,384 cycles # 2.765 GHz [66.68%] 2,868,753,319 stalled-cycles-frontend # 6.91% frontend cycles idle [50.01%] 30,162,193,535 stalled-cycles-backend # 72.60% backend cycles idle [50.01%] 11,161,722,533 instructions # 0.27 insns per cycle # 2.70 stalled cycles per insn [66.68%] 1,544,072,679 branches # 102.747 M/sec [49.99%] 52,536,867 branch-misses # 3.40% of all branches [49.99%] 15.027768835 seconds time elapsed ## lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0 Off-line CPU(s) list: 1-127 Thread(s) per core: 1 Core(s) per socket: 1 Socket(s): 1 NUMA node(s): 2 Model: 8335-GCA L1d cache: 64K L1i cache: 32K L2 cache: 512K L3 cache: 8192K NUMA node0 CPU(s): 0 NUMA node8 CPU(s): So either task migrations are being done to offline cpus or perf is accounting it wrong. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1575407/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
