ulimit

echo "* soft nofile 65535" >> /etc/security/limits.conf 
echo "* hard nofile 65535" >> /etc/security/limits.conf 
echo "* soft nproc 65535" >> /etc/security/limits.conf 
echo "* hard nproc 65535" >> /etc/security/limits.conf 
echo  "ulimit -n 65535"    >> /etc/profile
source /etc/profile

echo "UseLogin yes" >> /etc/ssh/sshd_config 
service sshd restart

echo "session    required     pam_limits.so"  >> /etc/pam.d/login 

在线修改limit参数
Can`t create a new thread 
cat /proc/[pid]/limits 
echo -n “MAX processes=204800:204800”> /proc/pid/limits

修改用户的.bash_profile
ulimit -u 65535