On 9/7/08, Linus Torvalds  wrote:

quoted text
>

>

>  On Sat, 6 Sep 2008, Jon Smirl wrote:

>  >

>

> > When I was playing with those giant Mozilla packs speed of zlib wasn't

>  > a big problem. Number one problem was the repack process exceeding 3GB

>  > which forced me to get 64b hardware and 8GB of memory. If you start

>  > swapping in a repack, kill it, it will probably take a month to

>  > finish.

>

>

> .. and you'd make things much much WORSE?

My observations on the Mozilla packs indicated that the problems were

elsewhere in git, not in the decompression algorithms. Why does a

single 2000 delta chain take 15% of the entire pack time? Something

isn't right when long chains are processed which triggers far more

decompressions than needed.
>

quoted text
>

>  > Size and speed are not unrelated.

>

>

> Jon, go away.

>

>  Go and _look_ at those damn numbers you tried to point me to.

>

>  Those "better" compression models you pointed at are not only hundreds of

>  times slower than zlib, they take hundreds of times more memory too!

>

>  Yes, size and speed are definitely not unrelated. And in this situation,

>  when it comes to compression algorithms, the relationship is _very_ clear:

>

>   - better compression takes more memory and is slower

>

>  Really. You're trying to argue for something, but you don't seem to

>  realize that you argue _against_ the thing you think you are arguing for.

>

>

>                 Linus

>

--

Jon Smirl

jonsmirl@gmail.com

--

To unsubscribe from this list: send the line "unsubscribe git" in

the body of a message to majordomo@vger.kernel.org

More majordomo info at  http://vger.kernel.org/majordomo-info.html