From: Roman Shaposhnik <rvs@sun.com>
Date: Sat, 19 Apr 2008 23:35:55 GMT
Subject: Re: Git performance on OS X
Message-ID: <A07C1A99-084B-4DFC-90CB-B8BDAF7E72EF@sun.com>
In-Reply-To: <alpine.LFD.1.10.0804191619240.2779@woody.linux-foundation.org>

On Apr 19, 2008, at 4:26 PM, Linus Torvalds wrote:
> This is the WebKit archive, right?
>
> For me, doing a "time git status ." on the WebKit thing I just  
> cloned from
> git://git.webkit.org/WebKit.git is much faster: 1.264s (and it goes  
> down
> by maybe 5-10% with my lstat-avoidance patch).
>
> Is there any system-level profiler for OS X to get a clue where  
> that cost
> is, in case it's not the lstat() at all?

If it happens on Leopard, DTrace would be a perfect way to query the  
system:

   $ dtrace -n 'syscall::*:entry /pid==$target/ { @[probefunc] = count 
(); }' -c "git <do stuff>"

E.g.:

$ dtrace -n 'syscall::*:entry /pid==$target/ { @[probefunc] = count 
(); }' -c "echo Hello World"
dtrace: description 'syscall::*:entry ' matched 234 probes
Hello World
dtrace: pid 1325 has exited

   fstat64                                                           1
   getpid                                                            1
   getrlimit                                                         1
   ioctl                                                             1
   mmap                                                              1
   munmap                                                            1
   rexit                                                             1
   sysi86                                                            1
   setcontext                                                        2
   write                                                             2


Thanks,
Roman.