Re: 2.5.44-[mm3, ac2] time to tar zxf kernel tarball comparedforvarious fs.

[Andrew Morton <akpm@digeo.com>]

Steven Cole wrote:
> 
> ...
> OK, here is the ext2 data.  This was done on my /tmp partition.
> 
> For ext2, the variation between runs was as much as between
> mm3 and ac2.  This data is from the first of 4 runs as before.
> 
> Steven
> 
> ext2
> tar zxf linux-2.5.44.tar.gz     2.5.44-mm3      2.5.44-ac2
> user                            4.17            4.16
> system                          2.76            2.7
> elapsed                         00:08.39        00:08.05
> % CPU                           82              85
> 

OK, so I assume what's happening here is that the entire uncompressed
kernel fits into 40% of your memory.

So we see 4 seconds user time from doing the gzip decompression
and three seconds system time; a little from reading the
tarball and most of it is creating a ton of dirty pagecache.

But most of the real cost has not been measured: getting that
dirty pagecache onto disk.  It has to happen sometime...

If you include a "sync" in the timing then you'll see the
benefit from the Orlov allocator.  You'll get that kernel
tree onto disk in half the time.