September 2004 - Darwin-dev

Re: swap files question.
by Mike Smith 09 Sep '04

09 Sep '04

I've wanted similar information in the past. In my case, I was debugging what appeared to be a weird memory leak. The number of swapfiles in /var/vm would grow to the hundreds, and eventually the system would run out of drive space and crash. Even after killing off all of our server processes we had a large number of files. It would have been handy to figure out which processes had active blocks in the swapfiles to know which process was the culprit. It would have been useful if there were some sort of "reverse" vmmap tool that would walk a swapfile and report the owner of each page contained in it. Note that the system will also move pages between swapfiles to compact swap. This is a time-consuming process, and swapfiles will take a while to disappear after they are no longer needed as the compaction process tries not to impact the system's overall performance. = Mike _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored. On Sep 8, 2004, at 10:00 PM, darwin-development-request(a)lists.apple.com wrote: This wouldn't tell you anything that you couldn't already tell by looking at the virtual size of running processes in the system. It would be less useful than you think; swapfile space is allocated on an as-needed basis, so for any process that has dirty pages in swap, you can reasonably assume that its pages are spread across all of the swapfiles in the system.

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Re: pthread_join
by Eric Albert 09 Sep '04

09 Sep '04

On Sep 8, 2004, at 11:49 PM, Marc Van Olmen wrote: ERRORS pthread_join() will fail if: Hope this helps, Eric _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored. Are there cases pthread_join doesn't work? Yes, so you should check the return value. From the man page: ----- RETURN VALUES If successful, the pthread_join() function will return zero. Otherwise an error number will be returned to indicate the error. [EINVAL] The implementation has detected that the value speci- fied by thread does not refer to a joinable thread. [ESRCH] No thread could be found corresponding to that speci- fied by the given thread ID, thread. [EDEADLK] A deadlock was detected or the value of thread speci- fies the calling thread. -----

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Re: Directory Access Plugin question
by Matt DeFoor 09 Sep '04

09 Sep '04

> > In the documentation for Open Directory plugins, there is reference to > > DirectoryAccessPlugin.h. Where is this header file located? If I try to > > implement the methods that the doc suggests, it seems that I would > > need to > > import DirectoryAccessPlugin.h. > > This file is not currently provided with the dev tools or the Directory > Services SDK. You could create a file with the appropriate declarations > from the documentation for now. > Do I need to create the file? The documentation for Directory Access Plugins is kinda sparse. There's a few things I'm not clear on. The doc says that the bundle's main class should implement at least setPluginAPIImplementor: and configureButtonClicked:. Do these actually have to go in main.m or can they be placed in my controller (controller.m)? Thanks, mattd _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored.

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pthread_join
by Marc Van Olmen 09 Sep '04

09 Sep '04

Hi In a thread A I want to wait until thread B finishes... pthread_join(B,NULL); FW_ASSERT(gThread_B_Finished==TRUE); Are there cases pthread_join doesn't work? regards, mvo _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored. At the end of the thread function B, I put a global gThread_B_Finished Boolean to true... just for testing that pthread_join(B,NULL); really worked.... I notice that sometimes this global variable is false!!! Which means pthread_join doesn't always works!!!

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Re: swap files question.
by Mike Laster 09 Sep '04

09 Sep '04

On Sep 4, 2004, at 7:08 AM, Mike Fischer wrote: > Hi Dieder, > > > Am 04.09.2004 um 03:06 schrieb Dieder Bylsma <applelist(a)spacemoo.com>: > >> Is there anyway to determine which program/process is paged out to a >> particular swap file? > > Err, I'm not a Darwin expert but AFAIK it doesn't really work that > way. The vm system pages out single memory pages (4096 byte blocks of > memory) not processes as a whole. So pages from a single process could > be paged out to multiple physical swap files. And most likely a > process will never be completly paged out. Only the least recently > used memory goes to disk when RAM is needed. > > Also some of the address space of a process may be memory mapped to > other files. These parts are usually (but not always) read only and > will not be written out to disk. They are simply discarded and > reloaded later when needed. > > And another point to note is that the location of a paged out memory > page may change over time. Consider for example the case where 4 swap > files of 64MB each are in use. Something happens on the system so that > lots of memory gets freed and thus more than 128MB of swap space are > left available. dynamic_pager will unregister a swap file in such a > case and cause the vm system to empty the file of any in use swap > space. Due to the fact that the remaining paged out memory is > scattered across all 4 swap files the vm system needs to move pages > around in order to empty one swap file so it can be deleted. (This is > probably a bit oversimplified. I am guessing that when "relocating" > paged out memory the system will probably reload them into RAM and > then decide in a separate step that some memory needs to go back out > to the swap files. This may or may not be the same pages just loaded > from the soon to be obsolete swap file.) > > This example assumes a non-standard setting for the dynamic pager in > Mac OS X 10.3: > dynamic_pager -H 33554432 -L 134217728 -S 67108864 -F > ${swapDir}/swapfile > similar to the settings in 10.2. The standard 10.3 configuration > creates swap files with increasing size instead of fixed size as in > this example but for demonstration purposes this is easier to handle. > > Finally note that the paged out memory will probably be completly out > of order in the swap files. You'd have a hard time piecing it back > together even if you knew where it was located. > > So why do you need to know where paged out memory pages are located? > > If it's security you're after then it would be a better idea to > prevent critical data to be paged out and erase its (RAM) memory right > after use. I've wanted similar information in the past. In my case, I was debugging what appeared to be a weird memory leak. The number of swapfiles in /var/vm would grow to the hundreds, and eventually the system would run out of drive space and crash. Even after killing off all of our server processes we had a large number of files. It would have been handy to figure out which processes had active blocks in the swapfiles to know which process was the culprit. The problem seemed to have mysteriously went away when we disabled some unused system services in /etc/hostconfig. It would have been useful if there were some sort of "reverse" vmmap tool that would walk a swapfile and report the owner of each page contained in it. [demime 0.98b removed an attachment of type application/pkcs7-signature which had a name of smime.p7s] _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored.

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Scheduled migration of darwin-development (new name darwin-dev) on lists.apple.com
by lists.apple.com Server Admins 08 Sep '04

08 Sep '04

Hello darwin-development list members- Apple is updating the hardware and software used to run our lists.apple.com server this Saturday (PDT). We are migrating our mailing list server to a new Apple Xserve with faster processors, more RAM, and larger disks. This will give us better performance in mail delivery, as well as on our lists.apple.com web site, plus room for future expansion. We are taking this opportunity to rename some of the mailing lists to establish a standard naming convention, therefore darwin-development will become darwin-dev. The migration will occur on September 11th, 2004 from 10am to 6pm PDT. During this time mailing list services and the lists.apple.com web site will not be available. We will make the migration as seamless as possible, however you will be subscribed to the migrated list as if it were a new list. Therefore, you will get a welcome message, with a random password confirming you have been subscribed to the new list. This is to be expected, and there will be no action required on your part. If you would like to change your password or any other subscription options, please visit http://lists.apple.com/mailman/listinfo/darwin-dev AFTER Septembert 11th, and follow the instructions at the bottom of the page for "darwin-dev subscribers". PLEASE TAKE NOTE: As of 9/11/04 darwin-development will be darwin-dev. After this migration mail will no longer be accepted by the old list name. If you are a member of multiple lists, you will receive multiple copies of similar messages. Thank you for your patience and we apologize for multiple copies. -lists.apple.com Server Admins _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored.

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Prebinding and Image Base Options
by Geoffrey Schmit 07 Sep '04

07 Sep '04

Reportedly, with the advent of 10.3.4, prebinding a framework is no longer beneficial. However, if I'm no longer prebinding my framework, is there any reason to continue to specify the -image_base linker option? Thanks! geoff _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored.

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Re: Open Directory Services & NetInfo: home directories and other things
by Finlay Dobbie 06 Sep '04

06 Sep '04

On 31 Aug 2004, at 04:59, Adhamh Findlay wrote: Well, you know, like, way to name the constants. -- Finlay _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored. "home" has always mapped to NFS home directories, or local directories. Rather than stomping on this they created the "home_loc" for AFP home directories. So the "right" one depends on which type of home directory you want the user to have.

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AFP sharepoints
by Herry Wiputra 06 Sep '04

06 Sep '04

Hi guys, Not sure which list are these questions belongs to, so I send it to both the development list and macos-x-server list. I've been trying to share a filesystem (not HFS+ or NFS) via AFP on my xserve, which is running MacOSX server 10.3.5. After reading some postings on the macos-x-server list, I found out that there are 3 ways of doing this. 1. Using the share facility in Workgroup Manager. If I use this facility to create a sharepoint on my filesystem, it will not get published. But if the sharepoint was on an HFS+ filesystem, it will get published. 2. Using third party tool, such as SharePoints, to modify the netinfo database. Same thing as number one. It only works on HFS+ filesystem but not on my own filesystem. 3. I read something about remounting nfs share over AFP. http://docs.info.apple.com/article.html?artnum=107077 I created /nfs_reshares directory and mount my filesystem within that directory. I opened up Workgroup Manager and found that my filesystem or the nfs_reshares directory are not published in Share->All, thus I can't set a sharepoint for it. However, if I do this with NFS filesystem, the NFS filesystem will show up in Share->All and I can set a sharepoint for it. This sharepoint will then get published. So my questions are: 1. Why do we need to create a special directory (nfs_reshares) to export an NFS mount via AFP? 2. If that was a special thing that Apple do to export NFS mounts over AFP, is that mean there is no chance to export other non-Apple filesystem via AFP? 3. Anybody ever tried to export ext2fs or other filesystem via AFP before? Thanks, Herry _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored.

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Re: swap files question.
by Mike Fischer 04 Sep '04

04 Sep '04

Hi Dieder, Am 04.09.2004 um 03:06 schrieb Dieder Bylsma <applelist(a)spacemoo.com>: Is there anyway to determine which program/process is paged out to a particular swap file? So why do you need to know where paged out memory pages are located? HTH Mike -- Mike Fischer Softwareentwicklung, EDV-Beratung Schulung, Vertrieb Web: <http://homepage.mac.com/mike_fischer/index.html> Note: I read this list in digest mode! Send me a private copy for faster responses. _______________________________________________ darwin-development mailing list | darwin-development(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-development Do not post admin requests to the list. They will be ignored. Err, I'm not a Darwin expert but AFAIK it doesn't really work that way. The vm system pages out single memory pages (4096 byte blocks of memory) not processes as a whole. So pages from a single process could be paged out to multiple physical swap files. And most likely a process will never be completly paged out. Only the least recently used memory goes to disk when RAM is needed. Also some of the address space of a process may be memory mapped to other files. These parts are usually (but not always) read only and will not be written out to disk. They are simply discarded and reloaded later when needed. And another point to note is that the location of a paged out memory page may change over time. Consider for example the case where 4 swap files of 64MB each are in use. Something happens on the system so that lots of memory gets freed and thus more than 128MB of swap space are left available. dynamic_pager will unregister a swap file in such a case and cause the vm system to empty the file of any in use swap space. Due to the fact that the remaining paged out memory is scattered across all 4 swap files the vm system needs to move pages around in order to empty one swap file so it can be deleted. (This is probably a bit oversimplified. I am guessing that when "relocating" paged out memory the system will probably reload them into RAM and then decide in a separate step that some memory needs to go back out to the swap files. This may or may not be the same pages just loaded from the soon to be obsolete swap file.) This example assumes a non-standard setting for the dynamic pager in Mac OS X 10.3: dynamic_pager -H 33554432 -L 134217728 -S 67108864 -F ${swapDir}/swapfile similar to the settings in 10.2. The standard 10.3 configuration creates swap files with increasing size instead of fixed size as in this example but for demonstration purposes this is easier to handle. Finally note that the paged out memory will probably be completly out of order in the swap files. You'd have a hard time piecing it back together even if you knew where it was located. If it's security you're after then it would be a better idea to prevent critical data to be paged out and erase its (RAM) memory right after use.

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