Re: Windows support

From: Marius Storm-Olsen <marius@trolltech.com>
Date: Jul 26, 2007, 09:30 UTC
Message-ID: <46A869A3.6050707@trolltech.com>
In-Reply-To: <alpine.LFD.0.999.0707251131540.3607@woody.linux-foundation.org>

Linus Torvalds said the following on 25.07.2007 20:43:

Show 11 quoted lines

> On Wed, 25 Jul 2007, Stephen Cuppett wrote:
>> I don't know if the performance problems are cygwin or not.  More
>>  knowledgeable people might be able to answer, it's just what I'm
>>  observing right now.  It could be more fundamental to the types
>> of access being performed en masse on inode-based versus NTFS
>> systems.
> 
> I think cygwin may add some overhead, but people should really
> realize that Linux is quite often an order of magnitude faster (or
> more) than other systems on some very basic operations.
>

(..snip..)

> 
> (It will just not be so *blazingly* fast, ie things like "git
> status" will generally not be instantaneous).

Let me present some numbers: My repository is ~680MB, and 19323 tracked files, in 2264 directories. When in a compiled state the total is 27540 files, in 4885 directories.

When file system cache is warm, I get the following times:
 Native: dir /B /S               1.077s
         dir /S                  1.707s (shows time, size/type)
 MSys:   ls -f1AUR              34.608s
         find . -type f          6.718s
         git diff (empty diff)   1.18s
         git status              5.5s
and when the system cach is cold:
         git status             54.55s

Maybe you guys have other git commands which are also/more interesting to look at/benchmark?

Windows people should also be aware that it's possible to tweak the amount of memory which the OS uses for the file cache. On XP you can change it _roughly_ in System Properties panel (Right-click on My Computer), then Advanced - Performance Settings - Advanced - Memory Usage: Normal setting is "Programs" for non-servers Windows systems, while you can select "System cache" make the OS allocate more memory for the system caches. I've tried both, and the setting doesn't really affect the file operations much when the cache is warm, but it probably affects how long the cache stays warm.

Also note that you can use Sysinternal's CacheSet (free), to
manipulate the working-set parameters of the system file cache.
You'll find that here:
    http://www.microsoft.com/technet/sysinternals/FileAndDisk/CacheSet.mspx

-- 
.marius