July 2004 - Darwin-kernel - lists.apple.com

Patch to msdosfs to hide dotfiles
by Joe Groff 31 Jul '04

31 Jul '04

I have a USB key that sees about equal use on Mac and Windows machines. When using the thing on Windows machines, the various dotfiles that OS X leaves on the filesystem can be distracting since Windows doesn't hide them as OS X and Unix do. To fix this, I made a patch to msdosfs that sets the 'hidden' and 'system' FAT attributes on files created with or renamed to names beginning with periods, thereby allowing Windows' Explorer to hide such files similarly to OS X's Finder: http://pknet.com/~joe/msdos-hidden-dotfiles.patch.bz2 The patch is made against the msdos-48 tarball from the Darwin 7.4 source distribution at http://www.opensource.apple.com/darwinsource/10.3.4/. It could use some extra sets of eyes before being applied to anything: * Since the msdosfs_rename function is a bit hairy and hard to follow, I'm not sure if the attribute-setting code is in the best place in that function. In particular, a well-timed error might cause the dot-ness (for lack of a better term) of the filename to get out of sync with the set attributes. * It'd probably be a good idea to make this a mount option rather than fixed behavior. However, should setting the attributes be the default behavior that a switch could turn off, or should it be special behavior requiring a switch to activate? (Forgive me if this isn't the right venue to discuss or submit patches to Darwin; Apple's website isn't terribly clear about the best way or place to do so.) -Joe _______________________________________________ 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.

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Re: gettimeofday() & the commpage
by Andrew Gallatin 30 Jul '04

30 Jul '04

Ed Wynne writes: > > On Jul 30, 2004, at 4:16 PM, Andrew Gallatin wrote: > > > So.. how the heck do you do it? Is the actual clock hardware mapped > > out to userspace? Or is there a trick I'm missing. > > It uses the PowerPC timebase registers which are accessible from > userland. They count some multiple of the external bus frequency, as > long as you know the conversation factor, its somewhat trivial (and > very fast) to convert to wall clock time units. Ah! That was the trick I was missing. Very cool. 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.

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Re: gettimeofday() & the commpage
by Ed Wynne 30 Jul '04

30 Jul '04

On Jul 30, 2004, at 4:16 PM, Andrew Gallatin wrote: So.. how the heck do you do it? Is the actual clock hardware mapped out to userspace? Or is there a trick I'm missing. It uses the PowerPC timebase registers which are accessible from userland. They count some multiple of the external bus frequency, as long as you know the conversation factor, its somewhat trivial (and very fast) to convert to wall clock time units. -Ed _______________________________________________ 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.

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gettimeofday() & the commpage
by Andrew Gallatin 30 Jul '04

30 Jul '04

I noticed that in Darwin 7.x you've optimized gettimeofday() by mapping some timecounter variables out into every process via the commpage. Very, very cool. I was concerned that it might yield results that were not accurate. Specifically, I was concerned that the kernel would not know to update the mapped-out timecounter variables more than once-per-clock tick as it would were gettimeofday() was always a syscall. So I wrote a tiny program which calls gettimeofday() in a tight loop, counting how many times it sees tv_usecs incremented. I was pleasantly surprised to see that its still very accurate (saw 998811 usec increments in a second). With 1 call to gettimeofday() according to ktrace. So.. how the heck do you do it? Is the actual clock hardware mapped out to userspace? Or is there a trick I'm missing. Impressed, 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.

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RE: How to get CPU cycles per sec?
by Lalit Chandivade 29 Jul '04

29 Jul '04

It looks like the value comes from gPEClockFrequencyInfo.cpu_frequency_hz. Is the value returned by clock_get_uptime() related with gPEClockFrequencyInfo.cpu_frequency_hz? For example if I want to measure 20 secs in terms of CPU cycles then can I say clock_get_uptime(current_time) reuired_time = current_time + 20 * gPEClockFrequencyInfo.cpu_frequency_hz; Will current_time be greater than or equal to required time after 20 sec? Thanks Lalit. -----Original Message----- From: darwin-kernel-admin(a)lists.apple.com [mailto:darwin-kernel-admin@lists.apple.com]On Behalf Of Paul Ripke Sent: Sunday, July 25, 2004 6:02 PM To: Lalit Chandivade Cc: darwin-kernel(a)lists.apple.com Subject: Re: How to get CPU cycles per sec? On Sunday, Jul 25, 2004, at 00:08 Australia/Sydney, Lalit Chandivade wrote: > Hi > > As per the following discussion > http://lists.apple.com/archives/darwin-kernel/2004/Mar/31/ > gettingsystemperfo > rmance.001.txt > > clock_get_uptime gives system up time in CPU cycles. > Is there a way in kernel or IOKit to know the CPU cycles per second? A little digging through xnu source should show where this is coming from: pbg3:ksh$ sysctl hw.cpufrequency hw.cpufrequency = 300000000 Cheers, -- Paul Ripke Unix/OpenVMS/TSM/DBA I love deadlines. I like the whooshing sound they make as they fly by. -- Douglas Adams _______________________________________________ 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.

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Re: Darwin Developers
by Olivier Kaloudoff 27 Jul '04

27 Jul '04

On Tue, 27 Jul 2004, Exinos Technologies wrote: > Hello > > I am sure there are many talented people are working on the Darwin Kernel > inside and outside of Apple, and hopefully some will be interested. > Without going in to too much detail, we are interested in developing a system > similar to FreeBSD's "Jail" for Darwin/OS X... > Would be interested to know if there is any interest in this? Maybe there is > something going on already by another company in this area? The Solucorp company has developped Linux-Vserver technology, that is now called VPS (Virtual Private Server), and is commercially supported by some other company. This software is GPLed and maintained by Herbert Pvtzl and was originally written by Solucorp.ca . It runs on linux and is there to fill the gap between linux chroot() and bsd jails.. Hope this information will help you to find contact or feedback about such projects. Best Regards, Olivier Kaloudoff LUG Linux Azur http://www.linux-azur.org _______________________________________________ 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.

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Re: infinite loop in ffs_sync()
by Quinn 27 Jul '04

27 Jul '04

At 18:27 +0300 27/7/04, Dan Bernstein wrote: By "track its progress" do you mean something more detailed than the "State" column on bugreport.apple.com? Not really. There are, however, other advantages to filing your own bugs. o You can make the case in your own words, rather than having it filtered through an Apple person. o When the DevBugs folks need to contact you, they can do it directly. o Less work for me (-: I find the lack of more detail very frustrating. I sympathise, but I don't know of any plans to improve this. Sorry. S+E -- Quinn "The Eskimo!" <http://www.apple.com/developer/> Apple Developer Technical Support * Networking, Communications, Hardware _______________________________________________ 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.

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Re: infinite loop in ffs_sync()
by Shawn Erickson 27 Jul '04

27 Jul '04

On Jul 27, 2004, at 8:27 AM, Dan Bernstein wrote: By "track its progress" do you mean something more detailed than the "State" column on bugreport.apple.com? I find the lack of more detail very frustrating. Then take that up with the bug reporter folks. <devbugs(a)apple.com> -Shawn _______________________________________________ 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.

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Re: Darwin Developers
by Exinos Technologies 27 Jul '04

27 Jul '04

Thank you. I am aware of existence of such software on Linux and FreeBSD, its the Mac OS X/Darwin that I am interested in. If any freelance developers know anything about this, or wish to talk to me about possibilities of developing such a system, my company is certainly interested in hearing about it. Thanks -- Mazdak Rezvani mazdak(a)exinos.com T: 416.857.3297 F: 416.352.5279 www.exinos.com The information in this email is confidential and is intended solely for the addressee(s). Access to this email by anyone else is unauthorized. If you are not an intended recipient, you must not read, use or disseminate the information contained in the email. On Jul 27, 2004, at 1:21 PM, Olivier Kaloudoff wrote: On Tue, 27 Jul 2004, Exinos Technologies wrote: Hello I am sure there are many talented people are working on the Darwin Kernel inside and outside of Apple, and hopefully some will be interested. Without going in to too much detail, we are interested in developing a system similar to FreeBSD's "Jail" for Darwin/OS X... Would be interested to know if there is any interest in this? Maybe there is something going on already by another company in this area? The Solucorp company has developped Linux-Vserver technology, that is now called VPS (Virtual Private Server), and is commercially supported by some other company. This software is GPLed and maintained by Herbert Pvtzl and was originally written by Solucorp.ca . It runs on linux and is there to fill the gap between linux chroot() and bsd jails.. Hope this information will help you to find contact or feedback about such projects. Best Regards, Olivier Kaloudoff LUG Linux Azur http://www.linux-azur.org _______________________________________________ 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.

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Re: infinite loop in ffs_sync()
by Dan Bernstein 27 Jul '04

27 Jul '04

By "track its progress" do you mean something more detailed than the "State" column on bugreport.apple.com? I find the lack of more detail very frustrating. -- Dan On Tue, 27 Jul 2004 13:01:57 +0100, Quinn <eskimo1(a)apple.com> wrote: > As an added benefit, if you file the bug yourself, you'll be able to > track its progress. _______________________________________________ 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.

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