1. Open the eclipse.ini file from your eclipse folder,see the picture below.
2. Open eclipse.ini in Notepad or any other text-editor application, Find the line -Xmx256m (or -Xmx1024m). Now change the default value 256m (or 1024m) to 512m. You also need to give the exact java installed version (1.6 or 1.7 or other).
Like This:
-Xmx512m
-Dosgi.requiredJavaVersion=1.6
OR
-Xmx512m
-Dosgi.requiredJavaVersion=1.7
OR
-Xmx512m
-Dosgi.requiredJavaVersion=1.8
Then it works well for me.