Re: Problem with large files on different OSes

On 27 May 2009, at 15:01, Tomas Carnecky wrote:

quoted

The problem appears to be the different maximum mmap sizes  
available on different OSes. Whic I don't really mind the maximum  
file size restriction git imposes, this restriction varying from OS  
to OS is very annoying, fixing this required rewriting history to  
remove the commit, which caused problems as the commit had already  
been pulled, and built on, by a number of developers.

If the requirement that all files can be mmapped cannot be easily  
removed, would be it perhaps be acceptable to impose a (soft?)  
1GB(ish) file size limit? I suggest 1GB as all the OSes I can get  
hold of easily (freeBSD, windows, Mac OS X, linux) support a mmap  
of size > 1GB.

I think this is a limitation of a 32bit build of git. I just tried  
with a 64bit build and it added the file just fine. The compiler on  
MacOSX (gcc) produces 32bit builds by default, even if the system  
supports 64bit executables. But gcc on 64bit Linux (at least the  
installations I have at home) produces a 64bit executables by  
default. Solaris/OpenSolaris behaves like MacOSX, no idea about *BSD  
or Windows. Maybe this is why git works on Linux but not MacOSX even  
on the same hardware.
Btw, I built git with: make install prefix=... CC="gcc -m64", no  
modifications needed (MacOSX 10.5.7).

The git installs I am using are all 32bit, this machine doesn't have a  
64bit processor (it is one of the few macs released without one). It's  
nice to know long term this problem will go away, that all suggests  
introducing some limit is not approriate, as while 32bit users have  
some arbitary limit above which they cannot go, I am sure all 64-bit  
OSes will manage to easily mmap any file. Of course warning such users  
they are producing packs that are not going to work on 32bit compiles  
of git isn't a stupid idea.

Chris