[Question] why multiple receviePings make user CPU Usage 100% in napi-busy-poll-server.c #1451
Description
I made message broadcasting server using napi-busy-poll-server examples. And I want to process batch completion to consume CQ faster. So, I need to submit multiple receivePings for that. In this case, if more than 2 receivePing(recvmsg) submission is submitted, than user's system cpu usage bursts as follow:
273 04:18:43 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
274 04:18:44 PM 0 10038 - 15.00 180.00 0.00 2.00 195.00 2 napi-busy-poll-
275 04:18:44 PM 0 - 10038 14.00 81.00 0.00 2.00 95.00 2 |__napi-busy-poll-
276 04:18:44 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
277
278 04:18:44 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
279 04:18:45 PM 0 10038 - 13.00 183.00 0.00 2.00 196.00 2 napi-busy-poll-
280 04:18:45 PM 0 - 10038 13.00 82.00 0.00 2.00 95.00 2 |__napi-busy-poll-
281 04:18:45 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
282
283 04:18:45 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
284 04:18:46 PM 0 10038 - 18.00 176.00 0.00 3.00 194.00 2 napi-busy-poll-
285 04:18:46 PM 0 - 10038 17.00 77.00 0.00 3.00 94.00 2 |__napi-busy-poll-
286 04:18:46 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
287
288 04:18:46 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
289 04:18:47 PM 0 10038 - 15.00 180.00 0.00 2.00 195.00 2 napi-busy-poll-
290 04:18:47 PM 0 - 10038 16.00 80.00 0.00 2.00 96.00 2 |__napi-busy-poll-
291 04:18:47 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
292
293 04:18:47 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
294 04:18:48 PM 0 10038 - 17.00 178.00 0.00 3.00 195.00 2 napi-busy-poll-
295 04:18:48 PM 0 - 10038 16.00 79.00 0.00 3.00 95.00 2 |__napi-busy-poll-
296 04:18:48 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
297
298 04:18:48 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
299 04:18:49 PM 0 10038 - 14.00 181.00 0.00 2.00 195.00 2 napi-busy-poll-
300 04:18:49 PM 0 - 10038 14.00 81.00 0.00 2.00 95.00 2 |__napi-busy-poll-
301 04:18:49 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
302
303 04:18:49 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
304 04:18:50 PM 0 10038 - 13.00 182.00 0.00 2.00 195.00 2 napi-busy-poll-
305 04:18:50 PM 0 - 10038 13.00 82.00 0.00 2.00 95.00 2 |__napi-busy-poll-
306 04:18:50 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
307
308 04:18:50 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
309 04:18:51 PM 0 10038 - 17.00 178.00 0.00 3.00 195.00 2 napi-busy-poll-
310 04:18:51 PM 0 - 10038 16.00 78.00 0.00 3.00 94.00 2 |__napi-busy-poll-
311 04:18:51 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
312
313 04:18:51 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
314 04:18:52 PM 0 10038 - 14.00 181.00 0.00 2.00 195.00 2 napi-busy-poll-
315 04:18:52 PM 0 - 10038 15.00 81.00 0.00 2.00 96.00 2 |__napi-busy-poll-
316 04:18:52 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
317
318 04:18:52 PM UID TGID TID %usr %system %guest %wait %CPU CPU Command
319 04:18:53 PM 0 10038 - 18.00 177.00 0.00 2.00 195.00 2 napi-busy-poll-
320 04:18:53 PM 0 - 10038 17.00 78.00 0.00 2.00 95.00 2 |__napi-busy-poll-
321 04:18:53 PM 0 - 10040 0.00 100.00 0.00 0.00 100.00 0 |__iou-sqp-10038
Why does this happen?