Re: cloning the kernel - why long time in "Resolving 313037 deltas"

Linus Torvalds [off-list ref] wrote:

On Tue, 19 Dec 2006, Shawn Pearce wrote:

quoted

Why isn't git-index-pack doing the same?  Is there some hidden glitch
in some OS somewhere that has a problem with overmapping a file and
appending into it via write()?  I've done that on Mac OS X, Linux,
BSDi, Solaris...  never had a problem.

It works on modern systems, but at least old HPUX versions had 
non-coherent mmap() and write(), and POSIX does not guarantee it. And if 
you ever want to port to Windows, I don't think you should do it.

Anyway, try the pread() version first, see if that fixes the OS X problem.

It does.  Without pread() (aka stock 'next') it takes me over an
hour to index a pack of linux-2.6.  With pread() its 1m6s to run
index-pack on the same pack file.  The indexes are (of course)
identically produced.

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