You may got this error because of insufficient amount of free Ram in your system. To find the current value on your system, run the following command.
[localhost@host]# cat /proc/sys/vm/min_free_kbytes
Now, raise the value. Try doubling, then quadrupling the value. Note that setting the value too low or too high could have detrimental effects on your system. Use the following command to modify the value of min_free_kbytes, substituting <value> with your intended value.
[localhost@host]# echo <value> > /proc/sys/vm/min_free_kbytes
Hope this will solve this error.