Re: [Census] So who uses git?

From: Linus Torvalds <torvalds@osdl.org>
Date: Feb 1, 2006, 16:25 UTC
Message-ID: <Pine.LNX.4.64.0602010815480.21884@g5.osdl.org>
In-Reply-To: <81b0412b0602010655i7b538bdck2baa216203279bce@mail.gmail.com>

On Wed, 1 Feb 2006, Alex Riesen wrote:

Show 8 quoted lines

> 
> $ time git update-index --refresh
> 
> real    0m21.500s
> user    0m0.358s
> sys     0m1.406s
> 
> WinNT, NTFS, 13k files, hot cache.

That's 25% less files than the Linux kernel, and I can do that operation in 0m0.062s (0.012s user, 0.048s system).

So WinNT/cygwin is about 2.5 _orders_of_maginitude_ slower here, or 340 times slower.

Now, I'm tempted to say that NT is a piece of sh*t, but the fact is, your CPU-times seem to indicate that most of it is IO (and the "real" cost is just 1.7 seconds, much of which is system time, which in turn itself is probably due to the IO costs too - so even that isn't comparable with the ).

Which may mean that you simply don't have enough memory to cache the whole thing. Which may be NT sucking, of course ("we don't like to use more than 10% of memory for caches"), but it might also be a tunable (which is sucky in itself, of course), but finally, it might just be that you just don't have a ton of memory. I've got 2GB in my machines, although 1GB is plenty to cache the kernel.

			Linus