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[英]How to find CPU utilization and memory usage after running a python script
[英]CPU utilization of python script when I used BPF filters
我从这里得到代码。
from binascii import hexlify
from ctypes import create_string_buffer, addressof
from socket import socket, AF_PACKET, SOCK_RAW, SOL_SOCKET
from struct import pack, unpack
sniff_interval=120
# A subset of Berkeley Packet Filter constants and macros, as defined in
# linux/filter.h.
# Instruction classes
BPF_LD = 0x00
BPF_JMP = 0x05
BPF_RET = 0x06
# ld/ldx fields
BPF_H = 0x08
BPF_B = 0x10
BPF_ABS = 0x20
# alu/jmp fields
BPF_JEQ = 0x10
BPF_K = 0x00
def bpf_jump(code, k, jt, jf):
return pack('HBBI', code, jt, jf, k)
def bpf_stmt(code, k):
return bpf_jump(code, k, 0, 0)
# Ordering of the filters is backwards of what would be intuitive for
# performance reasons: the check that is most likely to fail is first.
filters_list = [
# Must have dst port 67. Load (BPF_LD) a half word value (BPF_H) in
# ethernet frame at absolute byte offset 36 (BPF_ABS). If value is equal to
# 67 then do not jump, else jump 5 statements.
bpf_stmt(BPF_LD | BPF_H | BPF_ABS, 36),
bpf_jump(BPF_JMP | BPF_JEQ | BPF_K, 5201, 0, 5),
# Must be UDP (check protocol field at byte offset 23)
bpf_stmt(BPF_LD | BPF_B | BPF_ABS, 23),
bpf_jump(BPF_JMP | BPF_JEQ | BPF_K, 0x06, 0, 3),
# Must be IPv4 (check ethertype field at byte offset 12)
bpf_stmt(BPF_LD | BPF_H | BPF_ABS, 12),
bpf_jump(BPF_JMP | BPF_JEQ | BPF_K, 0x0800, 0, 1),
bpf_stmt(BPF_RET | BPF_K, 0x0fffffff), # pass
bpf_stmt(BPF_RET | BPF_K, 0), # reject
]
# Create filters struct and fprog struct to be used by SO_ATTACH_FILTER, as
# defined in linux/filter.h.
filters = ''.join(filters_list)
b = create_string_buffer(filters)
mem_addr_of_filters = addressof(b)
fprog = pack('HL', len(filters_list), mem_addr_of_filters)
# As defined in asm/socket.h
SO_ATTACH_FILTER = 26
# Create listening socket with filters
s = socket(AF_PACKET, SOCK_RAW, 0x0800)
s.setsockopt(SOL_SOCKET, SO_ATTACH_FILTER, fprog)
s.bind(('eth0', 0x0800))
while True:
data, addr = s.recvfrom(65565)
#print "*****"
print 'got data from', addr, ':', hexlify(data) #Have to print data, then only the CPU is 2%
我正在使用iperf3
进行测试,通过以太网电缆将另一台笔记本电脑传输到我的笔记本电脑。 服务器(“我的笔记本电脑”)在5021上列出,而客户端(“另一台笔记本电脑”)正在发送数据。
print 'got data from', addr, ':', hexlify(data)
并运行脚本,则该脚本的CPU使用率将提高30%,在100MB流量的情况下将提高40%。 print 'got data from', addr, ':', hexlify(data)
并再次运行,则在存在相同流量的情况下,CPU会降低到2%
。 我检查了htop
那么,这里的内容是什么?
我敢打赌hexlify()
或最有可能的print
(因为它必须与STDOUT同步)正在给您的主线程一个非常需要的休息时间和一个喘气的空间,而不是仅仅在无穷大的while
冲击套接字的读数环
尝试添加time.sleep(0.05)
(当然,首先要导入time
)而不是print语句,然后再次检查CPU使用率。
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