1、第 頁(yè)Linux下高cpu解決方案Linu*下高cpu解決方案1.用top指令查看哪個(gè)進(jìn)程占用CPU高gateway網(wǎng)關(guān)進(jìn)程14094占用CPU高達(dá)891%，這個(gè)數(shù)值是進(jìn)程內(nèi)各個(gè)線程占用CPU的累加值。PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND14094 root 15 0 315m 10m 7308 S 891% 2.2 1:49.01 gateway20642 root 17 0 17784 4148 2220 S 0.5 0.8 2:39.96 microdasys1679 root 18 0 10984 1856 1556

2、 R 0.3 0.4 0:22.21 sshd22563 root 18 0 2424 1060 800 R 0.3 0.2 0:00.03 top1 root 18 0 2156 492 460 S 0.0 0.1 0:01.59 init2.用top -H -p pid指令查看進(jìn)程內(nèi)各個(gè)線程占用的CPU百分比#top -H -p 14094top中可以看到有107個(gè)線程，但是下面9個(gè)線程占用CPU很高，下面以線程14086為主，分析其為何high CPUPID USER PR NI VIRT RES SHR S %CPU MEM TIME+ COMMAND14086 root 25 0 9

3、22m 914m 538m R 101 10.0 21:35.46 gateway14087 root 25 0 922m 914m 538m R 101 10.0 10:50.22 gateway14081 root 25 0 922m 914m 538m S 99 10.0 8:57.36 gateway14082 root 25 0 922m 914m 538m R 99 10.0 11:51.92 gateway14089 root 25 0 922m 914m 538m R 99 10.0 21:21.77 gateway14092 root 25 0 922m 914m 538m

4、R 99 10.0 19:55.47 gateway14094 root 25 0 922m 914m 538m R 99 10.0 21:02.21 gateway14083 root 25 0 922m 914m 538m R 97 10.0 21:32.39 gateway14088 root 25 0 922m 914m 538m R 97 10.0 11:23.12 gateway3.運(yùn)用gstack指令查看進(jìn)程中各線程的函數(shù)調(diào)用棧#gstack 14094 gstack.log在gstack.log中查找線程ID14086，由于函數(shù)棧會(huì)暴露函數(shù)環(huán)節(jié)，因此只顯示了兩個(gè)函數(shù)楨，線程ID

5、14086對(duì)應(yīng)線程號(hào)是37Thread 37 (Thread 0*4696ab90 (LWP 14086):#0 0*40000410 in _kernel_vsyscall ()#1 0*40241f33 in poll () from /lib/i686/nosegneg/libc.so.64.運(yùn)用gcore指令轉(zhuǎn)存進(jìn)程映像及內(nèi)存上下文#gcore 14094該指令生成core文件core.140945.用strace指令查看系統(tǒng)調(diào)用和花費(fèi)的時(shí)間#strace -T -r -c -p 14094-c參數(shù)顯示統(tǒng)計(jì)信息，去掉此參數(shù)可以查看每個(gè)系統(tǒng)調(diào)用話費(fèi)的時(shí)間及返回值。% time secon

6、ds usecs/call calls errors syscall 99.99 22.683879 3385 6702 poll0.00 0.001132 0 6702 gettimeofday0.00 0.000127 1 208 208 accept0.00 0.000022 22 1 read0.00 0.000000 0 1 write0.00 0.000000 0 1 close0.00 0.000000 0 14 time0.00 0.000000 0 2 stat640.00 0.000000 0 4 clock_gettime0.00 0.000000 0 7 send0.0

7、0 0.000000 0 10 10 recvfrom 100.00 22.685160 13652 218 total6.用gdb調(diào)試core文件，并線程切換到37號(hào)線程gcore和實(shí)際的core dump時(shí)產(chǎn)生的core文件幾乎一樣，只是不能用gdb進(jìn)行某些動(dòng)態(tài)調(diào)試(gdb) gdb gateway core.14094(gdb) thread 37Switching to thread 37 (Thread 0*4696ab90 (LWP 14086)#0 0*40000410 in _kernel_vsyscall ()(gdb) where#0 0*40000410 in _kernel_vsyscall ()#1 0*40241f33 in poll () from /lib/i686/nosegneg/libc.so.6可以依據(jù)具體的函數(shù)棧進(jìn)行g(shù)d