Re: [PATCH] refs.c: add a function to sort a ref list, rather then sorting on add

From: Julian Phillips <julian@quantumfyre.co.uk>
Date: Apr 17, 2007, 20:17 UTC
Message-ID: <Pine.LNX.4.64.0704172114040.8164@beast.quantumfyre.co.uk>
In-Reply-To: <Pine.LNX.4.64.0704170901170.5473@woody.linux-foundation.org>

On Tue, 17 Apr 2007, Linus Torvalds wrote:

Show 15 quoted lines

>
>
> On Tue, 17 Apr 2007, Julian Phillips wrote:
>>
>> Rather than sorting the refs list while building it, sort in one go
>> after it is built using a merge sort.  This has a large performance
>> boost with large numbers of refs.
>>
>> Signed-off-by: Julian Phillips <julian@quantumfyre.co.uk>
>
> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
>
> Looks fine. I think that even your new times are a bit high (over two
> seconds?) but things are clearly better. Have you looked at what takes so
> long now?

It's the tag auto-following code, I'm calling read_ref to see if I already have that tag - and it appears that doing that a few thousand times takes a while.

If I comment out that one line (so the code will _always_ think I have the tags - but I do have them, so ...) I get:

real 0m0.472s user 0m0.277s sys 0m0.181s

Looks like read_ref is the wrong thing to be using ...

-- 
Julian

  ---
"Life is like a buffet; it's not good but there's plenty of it."