April 2008 - Darwin-kernel - lists.apple.com

Re: kernel panic on readBytes
by Timur Alperovich 09 Apr '08

09 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=5iBUOrhtW2pndei2IV0W8I5aIEWmxfwNf9+QElYjHRY=; b=N/2jRQDvuO97IYqmq7kcxvQiVjr1HYhwN9DNONIqe+OGNXqBnRQ/zz+Ej9DzWD8VQK+q8+El+KMgO4lJmnqe2HkBL4yTsCI2lKpjxXP4MUetO0y7xH9Q/PMuSz1DviepvoHj1PlCaY5Ln7NTRGGjI9wdIf2S+Qe/2B4vEnHJrYg= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=a8P0n1X8LAflu4PfpX9hIGlfKCc0M48PPlCtfGvbfvjQN2gPTgz3Ux2W5V5wypXsEZ4XsbNL+c0lSs5pn4HpHlaaEpW6X+SmuN09cFobwNoNqJZJxjEPEouSdTpEIFqC5ezN3bsspRcm1TcDN34x4XoUYCVQNYpqGAocKXqmAe0= > The problem is that kMemoryTypePhysical != kIOMemoryTypePhysical64. The > former is a 32-bit I/O physical address. The later is a 64-bit CPU physical > address. > Right, makes sense. I tried doing what you described and ended up with: Unresolved kernel trap(cpu 1): 0x300 - Data access DAR=0x6572436D00001000 PC=0x00000000000B3E40 Latest crash info for cpu 1: Exception state (sv=0x26c76500) PC=0x000B3E40; MSR=0x00009030; DAR=0x00001000; DSISR=0x00200000; LR=0x000B26A8; R1=0x268F2A20; XCP=0x0000000C (0x300 - Data access) Backtrace: 0x000B2618 0x003622DC 0x26C95310 0x26C949AC 0x0037AA38 0x00377CB8 0x00093E0C 0x0002C1B4 0x00024C88 0x000B2C4C 0x00000000 backtrace terminated - frame not mapped or invalid: 0xBFFFE260 I hate to be the guy who posts code and asks for help, but I'm pretty stuck at this point, as the documentation I could find on this was scarce at best. Anyway, here is what I tried running: IOOptionBits opt = kIOMemoryTypePhysical64 | kIODirectionOut; struct IOPhysicalRange* range = (IOPhysicalRange*)IOMalloc(sizeof(struct IOPhysicalRange)); range->address = inStruct->offset; range->length = MEM_READ_CHUNK; task_t task; IOLog("calling withoptions\n"); IOSleep(2000); IOMemoryDescriptor* d = IOMemoryDescriptor::withOptions(range, 1, 0, task, opt); IOLog("withoptions ran\n"); IOSleep(5000); IOFree(range, sizeof(IOPhysicalRange)); if (d == NULL) { IOLog("IO-Init failed on the page %u\n", inStruct->offset); goto End; } ret = d->prepare(); if (ret != kIOReturnSuccess) { IOLog("IO-Prepare failed on the page %u\n", inStruct->offset); goto End; } char* buf = (char*) IOMalloc(MEM_READ_CHUNK); int copied; IOLog("printing: %d %d %d\n", (int)buf, MEM_READ_CHUNK, inStruct->offset); copied = d->readBytes(0, buf, MEM_READ_CHUNK); It prints out "calling with options" in the system log but not "withoptions ran". Did I screw up that call as well? Thank you, Timur _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Network stack/ethernet driver issues
by rimas＠cnmat.berkeley.edu 09 Apr '08

09 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Importance: Normal User-agent: SquirrelMail/1.4.9a-3.berkeley Greetings, Here's my situation: I have a custom piece of data logging hardware that generates about 50MB/sec of data and sends it out over a gigabit ethernet link as a steady stream of UDP packets (1k packet every ~20 microseconds, very periodic, not bursty at all) broadcasted to the local subnet. I want to log all this data to disk for offline analysis. As a first step I wrote a program to just listen for the UDP packets and verify that they were all being received. This is easy to do because each packet has a 16 bit sequence ID in it. Much to my dismay, I was unable to reliably achieve this. I am running 10.5.2 on a 2.33 gHz MacBook Pro with 2G of memory. After making SO_RCVBUF big enough, I was still occasionally missing a block of 100+ packets at a time. Looking in the system.log file I realized that each dropout was correlated to a message like: Apr 9 13:38:51 Macintosh-6 kernel[0]: AppleYukon2: 00000000,00000000 skgehw - cppSkDrvEvent - SK_DRV_RX_OVERFLOW: rcv fifo overflow Apr 9 13:38:51 Macintosh-6 kernel[0]: AppleYukon2: 00000000,00000000 sky2 - RX ring overflow -- dropped a packet and occasionally Apr 9 13:36:13 Macintosh-6 kernel[0]: AppleYukon2: 00000000,00000000 sky2 - RX ring overflow -- dropped a packet Apr 9 13:36:13 Macintosh-6 kernel[0]: AppleYukon2: 00000000,00000001 sk98osx sky2 - - sk98osx_sky2::replaceOrCopyPacket tried N times something else I should mention - just connecting my data logging hardware to the MacBook Pro causes a massive spike in CPU use (even when there's no program listening for the packets) with no listener running top reports 0-1% user, 49% system, 50% idle with the listener program running: 4% user, 85% system, 11% idle i decided to run Shark to see where the CPU time was going. here's the Time Profile of Everything for the first case (no listener) 55.4% 55.4% mach_kernel machine_idle 13.1% 13.1% mach_kernel ml_set_interrupts_enabled 7.9% 7.9% com.apple.iokit.AppleYukon2 yukon2osx::GetInterruptSource(unsigned long*) 3.4% 3.4% com.apple.iokit.AppleYukon2 yukon2osx::SkY2Isr(IOInterruptEventSource*, unsigned) 2.1% 2.1% mach_kernel lck_mtx_lock 1.9% 1.9% mach_kernel lck_mtx_unlock 1.9% 1.9% mach_kernel ifnet_input 1.9% 1.9% com.apple.iokit.AppleYukon2 yukon2osx::PrcocessInterruptSource(IOInterruptEventSource*, int) 1.2% 1.2% mach_kernel udp_input 1.0% 1.0% mach_kernel OSCompareAndSwap 1.0% 1.0% mach_kernel in_pcb_checkstate 0.7% 0.7% mach_kernel _mutex_assert 0.6% 0.6% mach_kernel ip_input 0.4% 0.4% mach_kernel udp_lock 0.4% 0.4% mach_kernel OSAddAtomic 0.4% 0.4% mach_kernel wait_queue_wakeup_all 0.3% 0.3% com.apple.iokit.AppleYukon2 yukon2osx::HandleReceives(int, unsigned short, unsigned, unsigned short, unsigned short, unsigned, unsigned short) 0.3% 0.3% mach_kernel cantrace 0.3% 0.3% mach_kernel IOWorkLoop::threadMain() 0.3% 0.3% mach_kernel udp_unlock 0.2% 0.2% mach_kernel IOWorkLoop::runEventSources() 0.2% 0.2% mach_kernel wait_queue_assert_wait 0.2% 0.2% mach_kernel ether_demux 0.2% 0.2% mach_kernel IORecursiveLockLock 0.2% 0.2% mach_kernel uiomove 0.2% 0.2% mach_kernel proto_input 0.1% 0.1% mach_kernel in_broadcast and here's the output for the second case (listener running) 22.2% 22.2% mach_kernel ml_set_interrupts_enabled 21.2% 21.2% mach_kernel machine_idle 4.7% 4.7% com.apple.iokit.AppleYukon2 yukon2osx::GetInterruptSource(unsigned long*) 4.6% 4.6% com.apple.iokit.AppleYukon2 yukon2osx::PrcocessInterruptSource(IOInterruptEventSource*, int) 4.6% 4.6% com.apple.iokit.AppleYukon2 yukon2osx::SkY2Isr(IOInterruptEventSource*, unsigned) 3.1% 3.1% mach_kernel lck_mtx_lock 2.6% 2.6% mach_kernel lck_mtx_unlock 1.7% 1.7% mach_kernel OSAddAtomic 1.4% 1.4% mach_kernel ifnet_input 1.3% 1.3% mach_kernel copyout_kern 1.2% 1.2% mach_kernel soreceive 1.1% 1.1% com.apple.iokit.AppleYukon2 yukon2osx::HandleReceives(int, unsigned short, unsigned, unsigned short, unsigned short, unsigned, unsigned short) 1.1% 1.1% mach_kernel _rtc _nanotime_read 1.0% 1.0% libSystem.B.dylib recvfrom$NOCANCEL$UNIX2003 0.9% 0.9% mach_kernel lo_unix_scall 0.8% 0.8% mach_kernel udp_input 0.8% 0.8% mach_kernel _mutex_assert 0.8% 0.8% mach_kernel ip_input 0.6% 0.6% mach_kernel wait_queue_assert_wait 0.6% 0.6% mach_kernel nval_copy_windows 0.5% 0.5% mach_kernel wait_queue_wakeup_all 0.5% 0.5% mach_kernel m_mclget 0.5% 0.5% mach_kernel uiomove 0.5% 0.5% mach_kernel sbappendaddr 0.5% 0.5% mach_kernel lck_rw_lock_shared 0.5% 0.5% mach_kernel cantrace 0.4% 0.4% mach_kernel udp_lock 0.4% 0.4% com.apple.iokit.AppleYukon2 yukon2osx::HandleStatusLEs() 0.4% 0.4% mach_kernel lck_mtx_lock_spinwait 0.4% 0.4% com.apple.iokit.AppleYukon2 yukon2osx::GiveRxBufferToHw(unsigned, int, s_packet*) 0.4% 0.4% mach_kernel blkclr 0.4% 0.4% mach_kernel socketpair 0.4% 0.4% mach_kernel udp_unlock 0.4% 0.4% mach_kernel zalloc_canblock 0.4% 0.4% mach_kernel IOWorkLoop::runEventSources() 0.4% 0.4% mach_kernel uiomove64 0.3% 0.3% mach_kernel unix_syscall 0.3% 0.3% libSystem.B.dylib recvfrom Ultimately I was unable to reliably receive all the packets the device was putting over the ethernet link due to the rx ring buffer overflowing. These overflows happen a few times a minute, regardless of whether or not an application is actually listening for the packets. Since I have Linux running on the same machine, I decided to try recompiling and running the same test program under Linux 2.6.24. Under Linux my test program receives every packet reliably and doesn't stress the machine out. For comparison, here is what top reports: with device attached, no listener 0.5% user, 0% system, 84% idle, 5% hardware interrupt, 4% software interrupt with the listener program running: 1% user, 3% system, 82% idle, 5% hardware interrupt, 9% software interrupt so it seems to me that something is screwy with the macos networking stack. It wasn't a big deal for me as I was able to get my data logging software running reliably under Linux but it doesn't seem right that macos can't keep up with a 50MB/sec network load (only about 40% of the available bandwidth on a gigabit ethernet link). Is this a known issue ? Should I file a bug report ? thanks -rimas _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: 64-bit/shared memory performance
by Terry Lambert 09 Apr '08

09 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com I need to: You can do that too. Yes. -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… On Apr 9, 2008, at 12:22 AM, Jamil J. Weatherbee wrote: I have grown extremely frustrated with the shm_open()/mmap() interface. In order to work with a shared memory object greater than 2GB I have had to "chain" together multiple segments of an object created with shm_open(). Sure. I even gave you the radar number on it, an told you why the limit exists in the first place. Now, here is my dilemma. I am specifically trying to avoid a multithreaded client/server architecture as a very much (in theory at this point) lower performance alternative to this. This depends on the scheduling scope for the threads - whether the quantum is awarded only on a process basis, or if it's awarded on a thread basis. When we used this model (including descriptor and similar rfork/sfork context sharing between processes) on the NetWare for UNIX implementation, it was done that way because the SVR4. {0/0.2/1/2} scheduler implementation was very poor. Note that this is only ever an issue if you are in an environment where you are competing for quantum with processes that are not associated with your implementation, and have not modified your priority. So the idea that you need to go to multiple processes rather than multiple threads in a single process is wrong-headed 1) Create a LARGE contiguous shared memory area (i.e. 4GB+) which is intended to actually be entirely resident in the physical RAM of the machine. You can do this. You simply can't do it all at once, which is not that big an issue, since what's taking the time is establishing page mappings into the address map, not the creation of the address map itself. 2) Access the shared memory area for read only by many client hundreds of processes in a speedy fashion. Speedy meaning that at present I have to shm_open() and mmap() together segments of 1GB in order to produce one large 4GB object in the individual client processes. This works fine but as soon as I try and READ the object it appears that the kernel is doing some kind of "COPY ON READ" as you can see in "top" that it takes about 6 seconds for RSIZE to grow to VSIZE. I am unclear on why this is happening as I am no VM expert --- especially since I am using the MAP_FIXED directive in mmap() so that the addresses are all the same in every processes virtual address space --- actually this is what makes the chaining work. I can only imagine that since it is the VM system writing some kind of kernel mappings. Here is where you are going off into the weeds. The thing that is taking the time is to map the page entries into the virtual address space of the new process. You established a shared region by pointing at the same region in multiple processes, but thee is no explicit association of the backing pages to the new object until you fault them by attempting to access them from the new process. 3) What I need is the fastest, most overhead free manner of directly accessing a segment of shared memory from multiple processes. These processes are spawned and die often and quickly. Actually, they are the result of .php scripts execing a small compiled C program on the local machine. This would normally be the domain of a SQL server or the like but this type of data access cannot be efficiently handled inside of a standard RDBMS architecture. I need top performance so the data query must be written in C and must have read access to the data in memory (the 4GB of shared memory is actually only an "index" to the real data which exists in secondary storage). Any help/suggestions would be greatly appreciated. I suggest that you start your new processes from a master process that forks after having read-touched the pages to establish the mappings in the first place. Once your 6 seconds of read-faulting is done in the master process, any process forked off that process will get a reference on the map instead of a copy of the map, and will not need to fault itself to establish duplicate mappings. Alternately, as I previously suggested, you can use Mach primitives to pass around address space references for the region between processes (and avoid the mmap/shm interfaces altogether). This requires that you learn about how Mach does things, however, and there's not a huge amount of documentation on that, other than the source code, or Amit Singh's (very large) book. This email sent to site_archiver(a)lists.apple.com

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Re: 64-bit/shared memory performance
by Jamil Weatherbee 09 Apr '08

09 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: 64-bit/shared memory performance
by Andreas Fink 09 Apr '08

09 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On 09.04.2008, at 07:22, Jamil J. Weatherbee wrote: Any help/suggestions would be greatly appreciated. -Jamil _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/afink%40list.fink.org _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… I can't comment on how the kernel does mmap in that respect but there's probably ways around this by instead of launching separate processes every time to use threads instead so they share the same memory by default. Or use a daemon which holds the memory and then answers queries by using a socket interface or the like. Of course it depends if it only has to search in >4G of data and return a s mall part or if its also a question of using large chunks of that data as the query answer. Launching/Killing processes is an expensive task. The initial memory mapping probably as well. I have grown extremely frustrated with the shm_open()/mmap() interface. In order to work with a shared memory object greater than 2GB I have had to "chain" together multiple segments of an object created with shm_open(). Now, here is my dilemma. I am specifically trying to avoid a multithreaded client/server architecture as a very much (in theory at this point) lower performance alternative to this. I need to: 1) Create a LARGE contiguous shared memory area (i.e. 4GB+) which is intended to actually be entirely resident in the physical RAM of the machine. 2) Access the shared memory area for read only by many client hundreds of processes in a speedy fashion. Speedy meaning that at present I have to shm_open() and mmap() together segments of 1GB in order to produce one large 4GB object in the individual client processes. This works fine but as soon as I try and READ the object it appears that the kernel is doing some kind of "COPY ON READ" as you can see in "top" that it takes about 6 seconds for RSIZE to grow to VSIZE. I am unclear on why this is happening as I am no VM expert --- especially since I am using the MAP_FIXED directive in mmap() so that the addresses are all the same in every processes virtual address space --- actually this is what makes the chaining work. I can only imagine that since it is the VM system writing some kind of kernel mappings. 3) What I need is the fastest, most overhead free manner of directly accessing a segment of shared memory from multiple processes. These processes are spawned and die often and quickly. Actually, they are the result of .php scripts execing a small compiled C program on the local machine. This would normally be the domain of a SQL server or the like but this type of data access cannot be efficiently handled inside of a standard RDBMS architecture. I need top performance so the data query must be written in C and must have read access to the data in memory (the 4GB of shared memory is actually only an "index" to the real data which exists in secondary storage). This email sent to afink(a)list.fink.org This email sent to site_archiver(a)lists.apple.com

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Re: 64-bit/shared memory performance
by Jamil J. Weatherbee 09 Apr '08

09 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com I have grown extremely frustrated with the shm_open()/mmap() interface. Any help/suggestions would be greatly appreciated. -Jamil _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… In order to work with a shared memory object greater than 2GB I have had to "chain" together multiple segments of an object created with shm_open(). Now, here is my dilemma. I am specifically trying to avoid a multithreaded client/server architecture as a very much (in theory at this point) lower performance alternative to this. I need to: 1) Create a LARGE contiguous shared memory area (i.e. 4GB+) which is intended to actually be entirely resident in the physical RAM of the machine. 2) Access the shared memory area for read only by many client hundreds of processes in a speedy fashion. Speedy meaning that at present I have to shm_open() and mmap() together segments of 1GB in order to produce one large 4GB object in the individual client processes. This works fine but as soon as I try and READ the object it appears that the kernel is doing some kind of "COPY ON READ" as you can see in "top" that it takes about 6 seconds for RSIZE to grow to VSIZE. I am unclear on why this is happening as I am no VM expert --- especially since I am using the MAP_FIXED directive in mmap() so that the addresses are all the same in every processes virtual address space --- actually this is what makes the chaining work. I can only imagine that since it is the VM system writing some kind of kernel mappings. 3) What I need is the fastest, most overhead free manner of directly accessing a segment of shared memory from multiple processes. These processes are spawned and die often and quickly. Actually, they are the result of .php scripts execing a small compiled C program on the local machine. This would normally be the domain of a SQL server or the like but this type of data access cannot be efficiently handled inside of a standard RDBMS architecture. I need top performance so the data query must be written in C and must have read access to the data in memory (the 4GB of shared memory is actually only an "index" to the real data which exists in secondary storage). This email sent to site_archiver(a)lists.apple.com

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Re: how to connect IONetworkingFamily source code on gdb
by Justin C. Walker 09 Apr '08

09 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On Apr 8, 2008, at 13:20 , Woojung.Huh(a)smsc.com wrote: HTH Justin -- Justin C. Walker, Curmudgeon-At-Large Institute for the Enhancement of the Director's Income -------- When LuteFisk is outlawed, Only outlaws will have LuteFisk -------- _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… I have kernel panic from my driver and it is linked to IONetworkingFamily. No problem to setup gdb, and be able to list source code of "xnu" part and my driver. But, I don't know and can not find the way to list source of IONetworkingFamily. I already downloaded IONetworkingFamily source and put into / SourceCache folder. Is it possible to see source of IONetworkingFamily from gdb? Yup. Check the 'add-' commands in gdb (these let you load symbols of various types) and the 'dir' command (to add a directory where the debugger will look for source files). This email sent to site_archiver(a)lists.apple.com

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Re: kernel panic on readBytes
by Quinn 08 Apr '08

08 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com >From reading the documentation about the IOMemoryDescriptor on developer.apple.com, it seems that calling "withPhysicalAddress" should set the kMemoryTypePhysical flag. S+E -- Quinn "The Eskimo!" <http://www.apple.com/developer/> Apple Developer Relations, Developer Technical Support, Core OS/Hardware _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… At 13:48 -0400 8/4/08, Timur Alperovich wrote: The problem is that kMemoryTypePhysical != kIOMemoryTypePhysical64. The former is a 32-bit I/O physical address. The later is a 64-bit CPU physical address. This email sent to site_archiver(a)lists.apple.com

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how to connect IONetworkingFamily source code on gdb
by Woojung.Huh＠smsc.com 08 Apr '08

08 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Hi, I have kernel panic from my driver and it is linked to IONetworkingFamily. No problem to setup gdb, and be able to list source code of "xnu" part and my driver. But, I don't know and can not find the way to list source of IONetworkingFamily. I already downloaded IONetworkingFamily source and put into /SourceCache folder. Is it possible to see source of IONetworkingFamily from gdb? Thanks in advance, Woojung _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: kernel panic on readBytes
by Timur Alperovich 08 Apr '08

08 Apr '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=4e5U9RhgYEWSrWwcVshnunJIl8h/6aurhw22ZkHbK88=; b=T4lHDzjlrLlviCEKgCImO1IyqrO0hpjSNmF1Vq6byVlbbWSpN+QlDC0cKZZZSR+wrHX5vCbqbzdRU8VTjkGz7BG48yQqz0HqEH8ZCRFZsd68bKynXtLOoCsJlS25eLDJ4oudWHfvshZ1s8o6+YDalxSwxD6ooDTByAQ6Lls2M2U= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=TPBfp0JKmmIrl1EoUMS+B3uTuq4IDNKspxghTCuFi29nou/xnzICaXGMO9+ZZwMp3L/LoVLOmFb7XQOmnt6S3e2O5LHx3+4QKT26LzU+cCFpZ7NMLj2tG5QeVUPry+3b29dO4IogFKZJxPuEqZqOiiCjLTGgpCWWRfGfWR8nbco= Quinn, Thanks for the explanation. > Of course, this doesn't help folks who are trying to access CPU physical > addresses (-: I am trying to read a page of physical memory and do an operation on its contents (hash) and then return it to the user. > I suspect you can work around this with the kIOMemoryTypePhysical64 flag, > but I haven't looked at it in depth. >From reading the documentation about the IOMemoryDescriptor on developer.apple.com, it seems that calling "withPhysicalAddress" should set the kMemoryTypePhysical flag. Also, I tried allocating memory with IOMalloc instead of throwing it on the kernel stack, which resulted in the same panic. Any other ideas? I guess I'll try setting the flags manually and see how that goes. Thank you, Timur _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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