Re: Kernel headers git tree

From: Linus Torvalds <torvalds@osdl.org>
Date: Jul 14, 2006, 01:08 UTC
Message-ID: <Pine.LNX.4.64.0607131806140.5623@g5.osdl.org>
In-Reply-To: <1152838562.31372.58.camel@shinybook.infradead.org>

On Fri, 14 Jul 2006, David Woodhouse wrote:

Show 12 quoted lines

>
> Btw, git-rev-list is _very_ slow at this. Even when the output is
> actually HEAD, it takes my 2.3GHz G5 a _long_ time to give a result:
> 
> pmac /pmac/git/linux-2.6 $ git-rev-parse HEAD
> ab6cf0d0cb96417ef65cc2c2120c0e879edf7a4a
> pmac /pmac/git/linux-2.6 $ time git-rev-list --max-count=1 --topo-order HEAD -- include
> ab6cf0d0cb96417ef65cc2c2120c0e879edf7a4a
> 
> real    0m18.840s
> 
> Is there a better way to do that step?

Umm.. On my poor little 1.6GHz laptop:

	[torvalds@evo linux]$ time git-rev-list --max-count=1 HEAD -- include
	ab6cf0d0cb96417ef65cc2c2120c0e879edf7a4a

	real    0m0.014s
	user    0m0.004s
	sys     0m0.012s

that's 0.014 sec. Not exactly slow.

Now, the --topo-order you have there does slow it down a lot:

	[torvalds@evo linux]$ time git-rev-list --max-count=1 --topo-order HEAD -- include
	ab6cf0d0cb96417ef65cc2c2120c0e879edf7a4a

	real    0m24.016s
	user    0m23.973s
	sys     0m0.016s

so now it takes 24 seconds, and gives the same result.

		Linus