*** fatal error - couldn't allocate heap or How to change cygwin's Maximum Memory

Problem :
In cygwin sometimes you may face get below


C:\>bash --login
      4 [main] bash 18324 c:\cygwin\bin\bash.exe: *** fatal error - couldn't allocate heap, Win32 error 487, base 0x6D0000, top 0x720000, reserve_size 323584, allocsize 327680, page_const 4096

Solution:


Read this link to understand and solve this issue 

http://www.cygwin.com/cygwin-ug-net/setup-maxmem.html

run below command  to fix it
regtool -i set /HKLM/Software/Cygnus\ Solutions/Cygwin/heap_chunk_in_mb 2048