这些命令是什么意思?
echo 20480 > /proc/sys/kernel/msgmax
echo 40960000 > /proc/sys/kernel/msgmnb
echo 2000 > /proc/sys/kernel/msgmni
echo 4194304 > /proc/sys/net/core/optmem_max
echo 4194304 > /proc/sys/net/core/rmem_default
echo 4194304 > /proc/sys/net/core/rmem_max
echo 4194304 > /proc/sys/net/core/wmem_default
echo 4194304 > /proc/sys/net/core/wmem_max