linuxloading的一點(diǎn)感想

1、linux loading 的一點(diǎn)感想linux 系統(tǒng)支持多線程，但是核心數(shù)較少的機(jī)器上測試 壓力較大。主要表現(xiàn)在 load average 。一個 4 核的主機(jī)， load average 達(dá)到 40. 此時 CPU 還有60-70% 的剩余，主要問題出在進(jìn)程調(diào)度。ksoftirqd/0 kworker/2:1 等核心進(jìn)程可以顯示Cpu0: 3.8%us, 23.1%sy,0.0%ni, 55.1%id,0.0%wa,0.0%hi,17.9%si, 0.0%stCpu1: 4.4%us, 31.1%sy,0.0%ni, 64.4%id,0.0%wa,0.0%hi,0.0%si, 0.0%st

2、Cpu2: 5.1%us, 25.3%sy,0.0%ni, 67.7%id,2.0%wa,0.0%hi,0.0%si, 0.0%stCpu3: 5.7%us, 18.2%sy,0.0%ni, 75.0%id,0.0%wa,0.0%hi,1.1%si, 0.0%st可以看出系統(tǒng)占用 CPU 很多，但用戶態(tài)的 CPU很低。之前使用 tcpreplay 來模擬測試多路用戶，同時啟動太多個 tcpreplay 就好出現(xiàn)上述情況，改善方法是將回放的包 mege 到一起，然后單進(jìn)程回放多個包。mege 成批量的 pcap 可以使用 C 調(diào)用 libpcap 的接口來合并：源碼/* * Copyright

3、(C) 2012 Altobridge, Inc * Written by: Tany <ziyang.tan> * */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <pcap/pcap.h>#include <assert.h>#include pcapfork.h#include <math.h>char errbufPCAP_ERRBUF_SIZE = 0;void pr

4、int_usage (void) printf (Usage: ./pcap-mege start_UE pcap_filern);void get_new_filename (char *newfilename, const char *filename) char *str; strcpy (newfilename, filename); if (str = strstr (newfilename, .pcap) = NULL) strcat(newfilename, _1w.pcap); else sprintf (str, _1w.pcap); int main (int argc,

5、char *argv) int start_UE,end_UE; FILE* fp; struct pcap_pkthdr *header; const u8 *data; pcap_t *pcap; pcap_t *newpcap; pcap_dumper_t *dump; char start256=0; char end256=0; strcpy (start, argvargc - 2); start_UE=atoi(start); strcpy (end, argvargc - 1); end_UE=atoi(end); char pcap_filename256=0; strcpy

6、 (pcap_filename, argvargc - 2);printf(pcap_filename=%stn,pcap_filename); char newpcap_filename256=0; get_new_filename(newpcap_filename,pcap_filename); printf(new_filename=%stn,newpcap_filename);newpcap = pcap_open_dead (DLT_EN10MB, 65535); dump = pcap_dump_open (newpcap, newpcap_filename);int a=star

7、t_UE;for(a=start_UE;a<end_UE;a+) sprintf(pcap _filename, %d, a); strcat (pcap_filename,-iu_user_dec.pcap); pcap = pcap_open_offline(pcap_filename, errbuf); if (pcap = NULL) printf (%srn, errbuf); print_usage (); exit (1); while (pcap_next_ex (pcap, &header, &data) = 1) pcap_dump(dump, header,data); pcap_close (pcap); pcap_