<div dir="ltr"><div>Hi,</div><div><br></div><div>When I was doing some performance testing, I found that the number of threads just doubled if I enabled the smp (erl -smp auto).  I haven't started to run anything, just wondering what the extra threads are doing with smp enabled ?</div><div><br></div><div><br></div><div>%% with smp option enabled, we have 22 thread running under beam.smp</div><div><br></div><div>484: ~/erlang/test  > top -H -p 699</div><div><br></div><div>top - 10:41:40 up 205 days, 22:31, 72 users,  load average: 1.22, 1.65, 1.97</div><div>Tasks:  22 total,   0 running,  22 sleeping,   0 stopped,   0 zombie</div><div>Cpu(s):  6.0%us,  4.7%sy,  0.0%ni, 88.8%id,  0.0%wa,  0.0%hi,  0.4%si,  0.0%st</div><div>Mem:     32241M total,    28556M used,     3684M free,      842M buffers</div><div>Swap:        0M total,        0M used,        0M free,    14000M cached</div><div><br></div><div>  PID   PR  NI  VIRT  RES  SHR S   %CPU %MEM    TIME+  COMMAND         </div><div>  699   20   0 1757m  20m 2980 S      0  0.1   0:00.05 beam.smp                                                                                                                        </div><div>  703   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  704   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  705   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  706   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  707   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  708   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  709   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  710   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  711   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  712   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  713   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  714   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  716   20   0 1757m  20m 2980 S      0  0.1   0:00.03 beam.smp                                                                                                                        </div><div>  717   20   0 1757m  20m 2980 S      0  0.1   0:00.22 beam.smp                                                                                                                        </div><div>  718   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  719   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  720   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  721   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp                                                                                                                        </div><div>  722   20   0 1757m  20m 2980 S      0  0.1   0:00.02 beam.smp                                                                                                                        </div><div>  723   20   0 1757m  20m 2980 S      0  0.1   0:00.02 beam.smp                                                                                                                        </div><div>  724   20   0 1757m  20m 2980 S      0  0.1   0:00.00 beam.smp              </div><div><br></div><div><br></div><div>%% with smp option disabled, we have 11 threads running under beam<br></div><div><br></div><div>484: ~/erlang/test  > top -H -p 31599</div><div><br></div><div>top - 10:39:35 up 205 days, 22:29, 72 users,  load average: 1.21, 1.88, 2.08</div><div>Tasks:  11 total,   0 running,  11 sleeping,   0 stopped,   0 zombie</div><div>Cpu(s): 50.0%us,  0.0%sy,  0.0%ni, 50.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st</div><div>Mem:     32241M total,    28549M used,     3691M free,      842M buffers</div><div>Swap:        0M total,        0M used,        0M free,    14000M cached</div><div><br></div><div>  PID   PR  NI  VIRT  RES  SHR S   %CPU %MEM    TIME+  COMMAND                                                                                                                         </div><div>31599   20   0 1579m  15m 2836 S      0  0.0   0:00.32 beam                                                                                                                            </div><div>31607   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31608   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31609   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31610   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31611   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31612   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31613   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31614   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31615   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam                                                                                                                            </div><div>31616   20   0 1579m  15m 2836 S      0  0.0   0:00.00 beam  </div><div><br></div><div><br></div><div>Br,</div><div>Alex</div></div>