September 2002 - Darwin-kernel

Re: fork/exec performance?
by Jim Magee 23 Sep '02

23 Sep '02

On Monday, September 23, 2002, at 05:20 PM, Andrew Gallatin wrote: After writing a software installation script to install a large software package using libtool, I noticed that the OSX fork/exec performance seems to be pretty bad. On the same hardware (dual 800MHz g4), using the same script, the elapsted time is a hair over 10 seconds on linux (2.4.18-smp). On OS-X, it is over 3 minutes! % /usr/bin/time ./GM_INSTALL <..> 181.25 real 5.58 user 293.31 sys lmbench shows an order of magnitude difference in fork time, and nearly as bad in exec: vfork() yields 100X (yes, 100 times, not percent more) the performance of fork() in most situations on Mac OS X. So, if you can live with vfork() requirements, please do so. Getting common tools to use it where appropriate appears to be the trick in your case. I don't think Linux has vfork(), so people tend to stick with just fork() in portable code. We have also looked at going straight to posix_spawn(). It avoids the need to clone the parent process when your real goal was just to exec() a new process in the first place. But that isn't available now. --Jim _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

fork/exec performance?
by Andrew Gallatin 23 Sep '02

23 Sep '02

After writing a software installation script to install a large software package using libtool, I noticed that the OSX fork/exec performance seems to be pretty bad. On the same hardware (dual 800MHz g4), using the same script, the elapsted time is a hair over 10 seconds on linux (2.4.18-smp). On OS-X, it is over 3 minutes! % /usr/bin/time ./GM_INSTALL <..> 181.25 real 5.58 user 293.31 sys lmbench shows an order of magnitude difference in fork time, and nearly as bad in exec: g4.local. Darwin 6.0 powerpc-apple-darwin6.0 797 g4 Linux 2.4.18- powerpc-linux-gnu 799 Processor, Processes - times in microseconds - smaller is better ---------------------------------------------------------------- Host OS Mhz null null open selct sig sig fork exec sh call I/O stat clos TCP inst hndl proc proc proc --------- ------------- ---- ---- ---- ---- ---- ----- ---- ---- ---- ---- ---- g4.local. Darwin 6.0 797 1.47 2.73 17.2 20.7 27.2 3.00 10.5 7517 17.K 41.K g4 Linux 2.4.18- 799 0.42 0.69 2.52 3.79 33.6 1.23 3.08 659. 2642 12.K Are there any plans to do something about this? Or do I just avoid shell scripts in general, and libtool in particular? Thanks, Drew _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

Re: NKEs and Static Libs
by Michael Cashwell 20 Sep '02

20 Sep '02

On Friday, September 20, 2002, at 04:27 PM, Brian Wotring wrote: > I think I recall a similar problem with my NKE, I just made sure I had > used the -mlong-branch, and -static flags when compiling the library. OK this is now even more interesting... Despite the LIBRARY_STYLE = STATIC setting, following Brian's lead I added the -mlong-branch and -static flags. This caused the library link to fail. I then started whittling down the library until it was 2 "return 0;" functions. Then everything compiled and linked including the NKE. So Brian's right here, -static must be explicitly stated. Without it the NKE refuses to link with the library regardless of what's in it. So that's some progress at least. I then added back the barest minimum of C++ code to the library: 2 simple super/sub classes with a virtual method and destructor. When I then attempt to compile the static library I get this: CompileCplusplus /Users/cashwell/Documents/dev/Drop5/odShimMac4/netShim/../bin/_tmp/ 00netShim.build/netShimLib.build/Objects-normal/ppc/init.o {standard input}:1169:FATAL:incompatible feature used: directive .non_lazy_symbol_pointer (must specify "-dynamic" to be used) Can C++ not be used in such a -static lib? Anybody know what a "non_lazy_symbol_pointer" is? And Brian, when you did this did your library use any C++? Thanks all, Mike _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

NKEs and Static Libs
by Michael Cashwell 20 Sep '02

20 Sep '02

Greetings everyone, Suspecting that my problem is a tools issue (either a bug or incorrect usage) I first went to the PB list. But it seems the NKE's special needs are apparently significant and someone with more knowledge of that is required. So now I'm trying on this list. For reasons of code factoring (and limiting the distribution of some sensitive source code) I'm trying to build an NKE with a portion of it coming from a static library. After some difficulty I think I have the library (done via Project Builder's new Library target assistant) building correctly. But the final link of the NKE is failing with a strange error message. The error initially was: ld: /Users/cashwell/Documents/dev/Drop5/odShimMac4/bin/Debug/darwin/ libnetShim.a(init.o) incompatible, file contains unsupported type of section 6 (__TEXT,__picsymbol_stub) in load command 0 (must specify "-dynamic" to be used) /usr/bin/g++3 -o "/Users/cashwell/Documents/dev/Drop5/odShimMac4/netShim/../bin/Debug/ darwin/netShim.kext/Contents/MacOS/netShim" "-L/Users/cashwell/Documents/dev/Drop5/odShimMac4/netShim/../bin" "-L/Users/cashwell/Documents/dev/Drop5/odShimMac4/bin/Debug/darwin" "-F/Users/cashwell/Documents/dev/Drop5/odShimMac4/netShim/../bin" -filelist "/Users/cashwell/Documents/dev/Drop5/odShimMac4/netShim/../bin/_tmp/ 00netShim.build/netShim.build/Objects-normal/LinkFileList" "-lnetShim" "-arch" "ppc" "-static" "-nostdlib" "-r" "-lkmodc++" "-lkmod" "-lcc_kext" Seeing the "pic" reference in the error, on a lark I added "-fno-pic" to the library. With that the error becomes: ld: /Users/cashwell/Documents/dev/Drop5/odShimMac4/bin/Debug/darwin/ libnetShim.a(init.o) incompatible, file contains unsupported type of section 5 (__DATA,__nl_symbol_ptr) in load command 0 (must specify "-dynamic" to be used) I'm at a loss here. Can someone point me to the problem? I just want to link a static library into an NKE. Thanks, Mike _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

Re: Is Everything Before the Login Panel Open Source?
by Jim Magee 19 Sep '02

19 Sep '02

On Thursday, September 19, 2002, at 12:29 PM, Bernie Zenis wrote: BTW, so, do we currently have a kernel that can emulate older versions? And drivers, etc.? No, although an "old" kernel can often support newer user-level bits than it was designed to run with. Just think about update installs. While running on an existing kernel, we replace all the user-level bits with new version. Every app launch after that point runs with the new /System bits. The kernel (and the user-level daemons) must deal with some applications running with new bits and others running with old bits. At some point even that breaks down. That's when we require a CD install (we can't cope with the mix of old and new user-level bits between the two versions). This may be an issue with the kernel, or an issue with user-level daemons or peer-to-peer frameworks. But its a pretty sure bet that its going to be an issue with something if you try to mix across these versions. Rarely does a kernel need to run with older /System bits (and by this I also mean /usr, /etc, /bin, etc... bits as well), so we rarely design that in. --Jim _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

Re: Is Everything Before the Login Panel Open Source?
by Bernie Zenis 19 Sep '02

19 Sep '02

On Thursday, September 19, 2002, at 06:55 AM, Peter Montagner wrote: IIRC, this would be a fair bit of work. Loading an environment off another /Users directory shouldn't be that hard. Getting Unix privileges right could be a lot harder. Suppose the second OSX install has a user that the boot install doesn't have. What happens? That user wont be in the netinfo database or anything. You could try merging multiple netinfo databases on boot, I don't know if that's possible (not an expert in netinfo). Also, what if a user on one install has the same UID as another different user on another install. Privileges would be pretty broken. OTOH, if you have the requirement that only users on other drives also on the boot system appear, it may work. But, AFAIK that would only work if the UIDs were also the same (ie. you created them in the same order). I'm not saying any of this is impossible but I think Mac OS X would fight you every inch of the way, unless you make some restrictions. Actually, none of the restrictions are that bad. I think the main point was to run different versions of OSX, right? In that case you'd really have to run off a different /System folder and possibly put the kernel into some kind of old version compatibility mode. I'd just restart ;-) LOL. It sounds like you would rather not even think about the problem. :-) Some of what you are saying sounds like authenticating a user from a different system to run on "this" system. That is not what I was thinking. I was thinking of using a single login panel as a way to log into other system. Think of it as booting "this" system, picking a user on another system, restarting, autologin to that user on that system... without the restart and the autologin. :-) The best (only?) way I can think of avoiding the restart is to run the other system off of the currently loaded kernel, drivers, etc. It is really just a convenience feature for the users (and us who probably switch between systems more than average users). The current method forces us to pick a system (thru Startup Disk) first, then a user. If we could pick a system and a user at the same time, we would be more productive, we could work hard and faster on our killer apps that would propel the Mac to the top! (Hint, hint, Apple :-) BTW, so, do we currently have a kernel that can emulate older versions? And drivers, etc.? -Bernie Peter On Thursday, September 19, 2002, at 08:35 AM, Bernie Zenis wrote: Hi, Is everything before the login panel Open Source? I want to know because I am trying to think of ways that Apple might implement an idea. The idea is to have a single login panel allow you to login to any account on any Mac OS X version on any disk/partition in your Mac. At first, this seems really hard because the OS is partially (or fully?) loaded by the time you get to the login panel. However, if everything before the login panel is Open Source, then it seems more possible. Or would it not really be possible because too much earlier software might not work with the latest kernel, etc.? Thanks, Bernie _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored. _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

Re: Is Everything Before the Login Panel Open Source?
by Peter Montagner 19 Sep '02

19 Sep '02

IIRC, this would be a fair bit of work. Loading an environment off another /Users directory shouldn't be that hard. Getting Unix privileges right could be a lot harder. Suppose the second OSX install has a user that the boot install doesn't have. What happens? That user wont be in the netinfo database or anything. You could try merging multiple netinfo databases on boot, I don't know if that's possible (not an expert in netinfo). Also, what if a user on one install has the same UID as another different user on another install. Privileges would be pretty broken. OTOH, if you have the requirement that only users on other drives also on the boot system appear, it may work. But, AFAIK that would only work if the UIDs were also the same (ie. you created them in the same order). I'm not saying any of this is impossible but I think Mac OS X would fight you every inch of the way, unless you make some restrictions. Actually, none of the restrictions are that bad. I think the main point was to run different versions of OSX, right? In that case you'd really have to run off a different /System folder and possibly put the kernel into some kind of old version compatibility mode. I'd just restart ;-) Peter On Thursday, September 19, 2002, at 08:35 AM, Bernie Zenis wrote: Hi, Is everything before the login panel Open Source? I want to know because I am trying to think of ways that Apple might implement an idea. The idea is to have a single login panel allow you to login to any account on any Mac OS X version on any disk/partition in your Mac. At first, this seems really hard because the OS is partially (or fully?) loaded by the time you get to the login panel. However, if everything before the login panel is Open Source, then it seems more possible. Or would it not really be possible because too much earlier software might not work with the latest kernel, etc.? Thanks, Bernie _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored. _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

Re: Is Everything Before the Login Panel Open Source?
by Andrew Pinski 19 Sep '02

19 Sep '02

The only thing that is not open sourced before the Login Panel is the Window Server which SystemStartup takes to. Thanks, Andrew Pinski On Wednesday, Sep 18, 2002, at 15:35 US/Pacific, Bernie Zenis wrote: Hi, Is everything before the login panel Open Source? I want to know because I am trying to think of ways that Apple might implement an idea. The idea is to have a single login panel allow you to login to any account on any Mac OS X version on any disk/partition in your Mac. At first, this seems really hard because the OS is partially (or fully?) loaded by the time you get to the login panel. However, if everything before the login panel is Open Source, then it seems more possible. Or would it not really be possible because too much earlier software might not work with the latest kernel, etc.? Thanks, Bernie _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored. _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

Is Everything Before the Login Panel Open Source?
by Bernie Zenis 18 Sep '02

18 Sep '02

Hi, Is everything before the login panel Open Source? I want to know because I am trying to think of ways that Apple might implement an idea. The idea is to have a single login panel allow you to login to any account on any Mac OS X version on any disk/partition in your Mac. At first, this seems really hard because the OS is partially (or fully?) loaded by the time you get to the login panel. However, if everything before the login panel is Open Source, then it seems more possible. Or would it not really be possible because too much earlier software might not work with the latest kernel, etc.? Thanks, Bernie _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0

(no subject)
by Dhananjay Kumar Singh 16 Sep '02

16 Sep '02

Hi All I have got a problem regarding the keyboard interface in my application using MAC OS X The ADBOp() method is there for MAC OS 9 for the same purpose. Basically i want to access(Blink) the LED's of the Apple Extended keyboard. What is the method or alternate of ADBOp() method for MAC OS X. Kindly Reply soon Regards Dhananjay @91-80-8520408-6265 **************************Disclaimer************************************ Information contained in this E-MAIL being proprietary to Wipro Limited is 'privileged' and 'confidential' and intended for use only by the individual or entity to which it is addressed. You are notified that any use, copying or dissemination of the information contained in the E-MAIL in any manner whatsoever is strictly prohibited. *************************************************************************** _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

1 0