Re: Can GCC use more than 4G while compiling ?

[Tomas Kalibera <kalibera at cs dot purdue dot edu>]

Ian Lance Taylor wrote:
> Tomas Kalibera <kalibera@cs.purdue.edu> writes:
>
>   
> > > What is the exact error message?  Are all the compiler binaries 64-bit
> > > executables?
> > >
> > >       
> > - "virtual memory exhausted: Cannot allocate memory"
> >     
>
> OK, that means that a call to mmap using MAP_ANONYMOUS returned
> MAP_FAILED with errno set to ENOMEM.  I see from the mmap man page
> that that can happen when the process's has reached the maximum number
> of mappings.  It seems at least possible that you are running out of
> maps before you are running out of memory.  On a GNU/Linux system you
> can see the maximum map count with "/sbin/sysctl vm.max_map_count".
> You can change that value using /sbin/sysctl -w.
>   

Thanks! This helped.

I assume that it might also help to override GGC_QUIRE_SIZE (now it's 
set in ggc-page.c to 256, when mmap is used). But I did not check.

Tomas