????????????????????issue??????????????????????????CPU????????????????????????????????????????п???? ?????????????
????1.??top???????????????CPU??
????gateway???????14094???CPU???891%????????????????????????CPU????????
PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
14094 root      15   0  315m  10m 7308 S 891%  2.2   1:49.01 gateway
20642 root      17   0 17784 4148 2220 S  0.5  0.8   2:39.96 microdasys
1679 root      18   0 10984 1856 1556 R  0.3  0.4   0:22.21 sshd
22563 root      18   0  2424 1060  800 R  0.3  0.2   0:00.03 top
1 root      18   0  2156  492  460 S  0.0  0.1   0:01.59 init
????2.??top -H -p pid?????????????????????CPU????
????#top -H -p 14094
????top?п????????107??????????????9????????CPU?????????????14086??????????????high CPU
PID USER      PR  NI  VIRT  RES  SHR S %CPU MEM    TIME+  COMMAND
14086root      25   0  922m 914m 538m R  101 10.0  21:35.46 gateway
14087 root      25   0  922m 914m 538m R  101 10.0  10:50.22 gateway
14081 root      25   0  922m 914m 538m S   99 10.0   8:57.36 gateway
14082 root      25   0  922m 914m 538m R   99 10.0  11:51.92 gateway
14089 root      25   0  922m 914m 538m R   99 10.0  21:21.77 gateway
14092 root      25   0  922m 914m 538m R   99 10.0  19:55.47 gateway
14094 root      25   0  922m 914m 538m R   99 10.0  21:02.21 gateway
14083 root      25   0  922m 914m 538m R   97 10.0  21:32.39 gateway
14088  root       25   0   922m 914m  538m R    97 10.0   11:23.12  gateway
????3.???gstack??????????и??????????????
????#gstack 14094 > gstack.log
??????gstack.log?в??????ID14086???????????????????????????????????????壬???ID14086?????????37
????Thread 37 (Thread 0x4696ab90 (LWP 14086)):
????#0  0x40000410 in __kernel_vsyscall ()
????#1  0x40241f33 in poll () from /lib/i686/nosegneg/libc.so.6
????4.???gcore??????????????????????
????#gcore 14094
??????????????core???core.14094
????5.??strace??????????ú????????
????#strace -T -r -c -p 14094
????-c??????????????????????????????????????????估???????
% time     seconds  usecs/call     calls    errors         syscall
------ ----------- ----------- --------- --------- ----------------------------
99.99   22.683879        3385      6702                      poll
0.00    0.001132           0      6702                      gettimeofday
0.00    0.000127           1       208       208          accept
0.00    0.000022          22         1                    read
0.00    0.000000           0         1                    write
0.00    0.000000           0         1                    close
0.00    0.000000           0        14                    time
0.00    0.000000           0         2                    stat64
0.00    0.000000           0         4                    clock_gettime
0.00    0.000000           0         7                    send
0.00    0.000000           0        10        10          recvfrom
------ ----------- ----------- --------- --------- ------------------------------
100.00   22.685160                 13652       218 total
????6.??gdb????core???????????л???37?????
????gcore??????core dump???????core????????????????????gdb?????Щ???????
(gdb) gdb gateway core.14094 (gdb) thread 37 [Switching to thread 37 (Thread 0x4696ab90 (LWP 14086))]#0  0x40000410 in __kernel_vsyscall () (gdb) where #0  0x40000410 in __kernel_vsyscall () #1  0x40241f33 in poll () from /lib/i686/nosegneg/libc.so.6
????????????????????????gdb?????????Щ??????????????????????λ?poll??????ú???CPU??
????????????漰??????????????????????????????????????????????????????
???????????????ID->???ID->???????????->???????????????->????????