May 2008 - Darwin-dev - lists.apple.com

Re: Getting processor description from sysctl
by Mike 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Thunderbird 2.0.0.14 (Macintosh/20080421) No. Processor Name: Intel Core 2 Duo _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Terry Lambert wrote: On May 14, 2008, at 7:28 PM, Mike wrote: Is there a way to get the description of the processor(s) using sysctl. I am interested in the specific processor name, not the family name. For example "Northwood", not "i386" or "x86". We care about the family and the capability bits, not the Intel marketing name for it. The first lets us grade binaries, and th second lets us write software that avoids attempting to use capabilities not present on a specific CPU. -- Terry I am not attempting to use this info to determine capabilities of the specific CPU. I need to write a system-profiler like feature and I need the name of the processor, not just the family. System Profiler provides the processor name, so there must be a way to get it. For example on the MacBook it reports: This email sent to site_archiver(a)lists.apple.com

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Re: Getting processor description from sysctl
by Terry Lambert 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com No. -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On May 14, 2008, at 7:28 PM, Mike wrote: Is there a way to get the description of the processor(s) using sysctl. I am interested in the specific processor name, not the family name. For example "Northwood", not "i386" or "x86". We care about the family and the capability bits, not the Intel marketing name for it. The first lets us grade binaries, and th second lets us write software that avoids attempting to use capabilities not present on a specific CPU. This email sent to site_archiver(a)lists.apple.com

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Getting processor description from sysctl
by Mike 15 May '08

15 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Thunderbird 2.0.0.14 (Macintosh/20080421) Thanks, Mike _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Is there a way to get the description of the processor(s) using sysctl. I am interested in the specific processor name, not the family name. For example "Northwood", not "i386" or "x86". This email sent to site_archiver(a)lists.apple.com

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Re: Section Alignment in mach-o files
by Terry Lambert 14 May '08

14 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com -- Terry On May 14, 2008, at 2:06 AM, MT <markturner(a)gmx.net> wrote: Thanks for any insight Mark _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/tlambert%40apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… According to the documentation on <http://developer.apple.com>, which you should probably read before you get too far into manipulating Mach- o files, the alignment is in memory. However, be aware that many people deal with "what works" rather than "what's documented", and therefore there could be all sorts of code making assumptions about physical layout of the file. As an example, when I did the 64 bit exec bringip in the kernel, I had the chicken and egg problem of not having 64 bit Mach-o binaries to load, and not being able to create them because I didn't have anything to load them with to know they had been created correctly. So I cheated; I "knew" that the Mach-o header was written in the first 4K, and I "knew" that the first 4K was incompletely used, and I "knew" that the first section after the header was aligned to a 4K boundary. Using these three assumptions not actually guaranteed anywhere in the ABI, I wrote a program to take a 32 bit Mach-o, convert the sections and load commands to 64 bit versions of themselves, and then proceeded to write code to load the resulting 32-in-64 binaries. The entire bringup of 64 bit exec was done on a dual G4, months before I had real G5 hardware. The normal admonition in these cases has been floationg around the IETF for years, but I'll repeat it here: be very strict in the data you generate, and as liberal as possible in the data you accept, if you want to ensure the highest probability of interoperability. I have a question about the section alignment specified in the load command in a mach-o file. Is the alignment only relevant for the virtual address, or also for the file offset? Some tests with otool seem to indicate that both the virtual address and the file offset seem to respect that alignment normally, but does it need to be this way? This email sent to tlambert(a)apple.com This email sent to site_archiver(a)lists.apple.com

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Re: access time changes vs. kevent observer?
by Terry Lambert 14 May '08

14 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thanks, -- Terry On May 14, 2008, at 8:35 AM, Jim Correia <jim.correia(a)pobox.com> wrote: Which is the correct case? Jim _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/tlambert%40apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… It's not that clear to me that what you are presuming is the source of the NOTE_ATTRIB wakeups is in fact the actual source of them. Your assumption that this is due to atime updates may not be correct. Even if it is correct, however, there is room for interpretation from both the POSIX side of things (i.e. should events trigger as a result of "shall be marked for update" v.s. "shall be updated") and the philosophical side of things (i.e. is resource fork information data or metadata, and are events on it events on the fork or events on the file to which the fork is attached?). It would probably be best if you filed a bug, including with it sample code to demonstrate it properly (likely two programs, one to observe, one to trigger), along with an explanation as to why you think it's a bug. I have a file that I am observing with kevents. I am observing with the NOTE_ATTRIB flag set. (For this test case, I am using an HFS+ disk on Leopard.) Most things which bump the access time of the file do not cause my kevent observer to fire. (For example, `cat filename` bumps the access time, doesn't fire the kevent.) Some things, however, do. Any operation which causes the custom icon to be read from the resource fork (by opening the file in any Mac OS X GUI application.) bumps the access date and fires a kevent. I'm interested in many of the changes that come along with NOTE_ATTRIB, but I don't really care about the access date. Any advice for ignoring events for which only the access date change? This email sent to tlambert(a)apple.com This email sent to site_archiver(a)lists.apple.com

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Re: access time changes vs. kevent observer?
by Dave Zarzycki 14 May '08

14 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On May 14, 2008, at 9:48 AM, Jim Correia wrote: On May 14, 2008, at 12:33 PM, Dave Zarzycki wrote: I filed a bug a few months ago in this regard: Jim, Good luck, davez _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… 5435816 Add a NOTE_ATIME option to EVFILT_VNODE events Is your intention to separate out atime from the rest of the attributes? (That would be perfect.) Yes, although I have no idea when my peers might find the time to work on the above enhancement request. For now, you'll just need to ignore some spurious wakeup events. The current behavior seems wrong at least from the point of view that it is inconsistent. I'm getting NOTE_ATTRIB for some atime changes, but not all. What is the expected behavior here today? (Should I separately file a bug about this, or does your bug above cover this case?) I suspect that the NOTE_ATTRIB is accurate. What is probably happening is that an attribute of the file is changing, but you haven't discovered which one yet. I don't know why you are observing what you are, nor do I have the time to look into it. Sorry… Do you have any advice for how I can detect a spurious atime wakeup from other meaningful attribute changes? (As time marches on, and more metadata is added to Mac OS X, trying to cache the last set of attributes and compare to the current set seems like a bad solution to this problem.) Remember the previous values that you're interested in and compare current values the next time you wake up. If they are all the same, then you were spuriously woken up. This email sent to site_archiver(a)lists.apple.com

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Re: Panic Log Debugging?
by Garth Cummings 14 May '08

14 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Hi Duane, On May 14, 2008, at 10:44 AM, Duane Murphy wrote: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Thanks, Try <http://developer.apple.com/technotes/tn2002/tn2063.html>. HTH, --gc -----BEGIN PGP SIGNATURE----- Version: PGP Desktop 9.8.2 (Build 3005) Charset: ISO-8859-1 wsBVAwUBSCslFUrg9acQ4r2CAQhzpAgA9q5rff8qaw9NkLJvEHVjwz5F0q/fqr6d PuEeOQvjdD783g5dbVy5fSNSeOcILdh9Ut81dZM0iI9528VT5fY465izwm/m5NiL qoLrL9YKBQFSPTIl0eMu/n9tFzWNbu+2/pkybNebieW7sw/y11yQeAv8P7OpzeRa sTHrDOwv/cief3KThpiGGkZxf4SfoOPUpDEh/7x0ottQWXuOwkj1kPxbEEEjWIAk U1BcaTYS//yJIyc53pYHI1WDhBeLqt+l8rIeA9x3XFrUy5zLBREmeHaaPKC9zVEZ zt2Yw7TPIxRNlKsvF3lPG2VRoUJtW4q5T+hBRw6eJQK5GO5nhcHw6A== =fIxq -----END PGP SIGNATURE----- _______________________________________________ ____________________________________________________________________ Garth Cummings gcummings(a)apple.com Sr. Software Engineer Apple Developer Technical Support <http://developer.apple.com/technicalsupport> WWDC 2008 • June 9-13 • Moscone West • San Francisco, CA <http://developer.apple.com/wwdc/> _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… How can I convert a panic log backtrace dump into symbols for debugging? I seem to recall an article about how to do this, but I can't seem to find it. ...Duane This TN hasn't been updated for Intel processors yet, but the process for decoding a backtrace is nearly identical. Since Intel instructions are not fixed size, use "disass <address>" to disassemble the entire function to find the instruction referenced from the backtrace. This email sent to site_archiver(a)lists.apple.com

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Panic Log Debugging?
by Duane Murphy 14 May '08

14 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 How can I convert a panic log backtrace dump into symbols for debugging? I seem to recall an article about how to do this, but I can't seem to find it. Thanks, ...Duane -----BEGIN PGP SIGNATURE----- Version: PGP Desktop 9.8.2 (Build 3005) Charset: ISO-8859-1 wsBVAwUBSCslFUrg9acQ4r2CAQhzpAgA9q5rff8qaw9NkLJvEHVjwz5F0q/fqr6d PuEeOQvjdD783g5dbVy5fSNSeOcILdh9Ut81dZM0iI9528VT5fY465izwm/m5NiL qoLrL9YKBQFSPTIl0eMu/n9tFzWNbu+2/pkybNebieW7sw/y11yQeAv8P7OpzeRa sTHrDOwv/cief3KThpiGGkZxf4SfoOPUpDEh/7x0ottQWXuOwkj1kPxbEEEjWIAk U1BcaTYS//yJIyc53pYHI1WDhBeLqt+l8rIeA9x3XFrUy5zLBREmeHaaPKC9zVEZ zt2Yw7TPIxRNlKsvF3lPG2VRoUJtW4q5T+hBRw6eJQK5GO5nhcHw6A== =fIxq -----END PGP SIGNATURE----- _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: access time changes vs. kevent observer?
by Jim Correia 14 May '08

14 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On May 14, 2008, at 12:33 PM, Dave Zarzycki wrote: I filed a bug a few months ago in this regard: Thanks, Jim _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… 5435816 Add a NOTE_ATIME option to EVFILT_VNODE events Is your intention to separate out atime from the rest of the attributes? (That would be perfect.) For now, you'll just need to ignore some spurious wakeup events. The current behavior seems wrong at least from the point of view that it is inconsistent. I'm getting NOTE_ATTRIB for some atime changes, but not all. What is the expected behavior here today? (Should I separately file a bug about this, or does your bug above cover this case?) Do you have any advice for how I can detect a spurious atime wakeup from other meaningful attribute changes? (As time marches on, and more metadata is added to Mac OS X, trying to cache the last set of attributes and compare to the current set seems like a bad solution to this problem.) This email sent to site_archiver(a)lists.apple.com

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Re: access time changes vs. kevent observer?
by Dave Zarzycki 14 May '08

14 May '08

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Jim, I filed a bug a few months ago in this regard: 5435816 Add a NOTE_ATIME option to EVFILT_VNODE events For now, you'll just need to ignore some spurious wakeup events. Cheers, davez On May 14, 2008, at 8:35 AM, Jim Correia wrote: Which is the correct case? Jim _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/zarzycki%40apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… I have a file that I am observing with kevents. I am observing with the NOTE_ATTRIB flag set. (For this test case, I am using an HFS+ disk on Leopard.) Most things which bump the access time of the file do not cause my kevent observer to fire. (For example, `cat filename` bumps the access time, doesn't fire the kevent.) Some things, however, do. Any operation which causes the custom icon to be read from the resource fork (by opening the file in any Mac OS X GUI application.) bumps the access date and fires a kevent. I'm interested in many of the changes that come along with NOTE_ATTRIB, but I don't really care about the access date. Any advice for ignoring events for which only the access date change? This email sent to zarzycki(a)apple.com This email sent to site_archiver(a)lists.apple.com

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