This is happening on a 2017 15' MBP for reference. Info submitted to Apple below. Since upgrading to 11.3, every morning when I open my Macbook Pro, I have to restart it as it shuts down over night due to a kernel panic.This chapterQuestion: Q: Cleaning System and Kernel Cache. I restarted back into Safe Mode and did a medium cleanse of all the caches and was able to get it to boot back into OS X in normal mode.Features that can facilitate analysis of a kernel crash dump. I did a basic cleaning, which cured my trackpad issues from before, but did not cure my kernel panic problem. And a data issue with my main pool that caused a kernel panic on boot.The Oracle Solaris kernel memory (kmem) allocator provides a powerful set of debuggingI downloaded a program called Leopard Cache Cleaner and loaded it while in Safe Mode.This kernel refactor PR focuses on modifying how the JIT (Just-in-time.Specifically for the allocator. Noticed a strange occurrence that Bluetooth shows connected every so often to my iPhone.Discusses these debugging features, and the MDB dcmds and walkers designed8 - Fix crash that sometimes happened after shader cache load in dbghelp. Update: After a software upgrade of 10.15.7 to 11.0.1 kernel panics on shutdown or restart still prevail.Setting kmem_flagsKernel memory allocator contains many advanced debugging features, but theseAre not enabled by default because they can cause performance degradation.In order to follow the examples in this guide, you should turn on these features.You should enable these features only on a test system, as they can causePerformance degradation or expose latent problems.The allocator's debugging functionality is controlled by the kmem_flags tunable. Information provided in this guideAbout the kernel memory allocator might not be correct or applicable to pastGetting Started: Creating a Sample Crash DumpThis section shows you how to obtain a sample crash dump, and how toInvoke MDB in order to examine it. This guide reflects the Oracle Solaris kernel implementation asOf the date of publication of this guide. Refer to the header file for the definitions of allocator data structures.The kmem debugging features can be enabled on a production system to enhanceProblem analysis, or on development systems to aid in debugging kernel softwareMDB exposes kernel implementation details that are subject toChange at any time.
First, confirmThat dumpadm is configured to save kernel crash dumps andThat savecore is enabled. Forcing a Crash DumpNext step is to make sure crash dumps are properly configured. Remember to remove your /etc/system modifications before returning this system to production use. When the system reboots, confirm that kmem_flags is set to f. Cache Cleaner Kernel Panic Free Up SpaceYou can free up space and run savecore(1M) manually as root to subsequentlyIf your dump directory contains multiple crash dumps, the one you justCreated is the unix. When finished, a message is printedOn the system console: Sep 17 10:47:23 testsystem savecore: Decompress the crash dump withSep 17 10:47:23 testsystem 'savecore -vf /var/crash/testsystem/vmdump.0'If the message does not appear right away, check to whether savecore(1M) is still running:If your dump directory contains no dump files , then that partitionMight be out of space. # reboot -dSep 28 17:51:18 testsystem reboot: rebooted by rootPanic/thread=70aacde0: forced crash dump initiated at user request401fbb10 genunix:uadmin+55c (1, 1, 0, 6d700000, 5, 0)%l0-7: 00000000 00000000 00000000 00000000 00000000 00000000 00000000When the system reboots, savecore runs automaticallyTo preserve the crash dump in a file. Mac picture editing for slimming bodiesBuffer StatesThe functional domain of the kernel memory allocator is the set of buffers of virtual memory that make up the kernel heap. All of the techniques presented here are applicable to a64-bit kernel, and care has been taken to distinguish pointers (sized differentlyOn 32- and 64-bit systems) from fixed-sized quantities, which are invariantAn UltraSPARC workstation was used to generate the example presented.Your results can vary depending on the architecture and model of system youThe kernel memory allocator's job is to parcel out regions of virtualMemory to other kernel subsystems (these are commonly called clients).This section explains the basics of the allocator's operation and introducesSome terms used later in this guide. You can use savecore(1M) either locally or remotelyTo control the particular paths of the dump device and the savecore directory.To quickly examine files in the directory:Unix.0: ELF 64-bit MSB executable SPARCV9 Version 1, UltraSPARC3 ExtensionsRequired, statically linked, not stripped, no debugging information availableVmcore.0: SunOS 5.11 Generic 64-bit SPARC crash dump from 'testsystem'Vmdump.0: SunOS 5.11 Generic 64-bit SPARC compressed crash dump from 'testsystem'Now, run mdb on the crash dump you created, and checkLoading modules: Debugging crash dump vmcore.1 (32-bit) from testsystemPanic message: forced crash dump initiated at user requestIn the examples presented in this guide, a crash dump from a 32-bitKernel is used. Saving a Crash DumpWhen the system panics, or when you enter reboot -d, the following kinds of messages appear on the console: Sep 17 10:47:23 testsystem savecore: Decompress the crash dump withEnter the following # savecore -vf /var/crash/testsystem/vmdump.0Savecore: System dump time: Thu Sep 17 10:43:20 2009Savecore: saving system crash dump in /var/crash/testsystem/.0Loading modules: [ unix genunix specfs dtrace zfs scsi_vhci sd mpt px mac ldc sockfsIp hook neti sctp arp usba stmf qlc fctl nca lofs idm logindmux ptm ufs md cpc spppRandom smbsrv nfs crypto mdesc nsctl sdbc sv rdc fcp fcip ii nsmb ]To another system for analysis. If no clientOf the allocator holds a pointer to an allocated buffer, this buffer is saidTo be leaked, because it cannot be freed. The remainingBuffers are allocated, which means that a pointer toThat buffer has been provided to a client of the allocator. SomeOf these buffers are currently free, which means thatThey have not yet been allocated to any client of the allocator. Each cache contains a set of buffers. Sleeping and Non-Sleeping AllocationsThe Standard C Library's malloc(3C) function,The kernel memory allocator can block (or sleep), waitingUntil enough virtual memory is available to satisfy the client's request.This is controlled by the flag parameter to kmem_alloc(9F). Additionally, theAllocator has facilities for logging transactions for post-mortem examination. The allocator can verify that theState of a buffer is valid as part of each transaction. TransactionsA kmem transaction is a transition on a bufferBetween the allocated and free states. In this case, the kmem_alloc_16 cache handles all client requests for 9-16 bytes ofMemory. For example, the kernel has kmem_alloc_8 and kmem_alloc_16 caches. Each of these caches satisfiesRequests whose size is between the buffer size of that cache and the bufferSize of the next smallest cache. These caches provide memoryTo clients of kmem_alloc(9F) and kmem_zalloc(9F). Do NOT write code that relies on them, becauseThey are subject to change or removal in future releases of Oracle Solaris.Whose name begins with “ kmem_alloc_” implementThe kernel's general memory allocation scheme. Memory from these caches is allocated to clients by the kmem_cache_alloc() function and freed by the kmem_cache_free() function.Kmem_cache_alloc() and kmem_cache_free() areNot public DDI interfaces. You can learn about the various kmem caches on theSystem by issuing the ::kmastat command. Kernel Memory CachesThis section explains how to find and examineKernel memory caches. These include those caches whose namesStart with “ kmem_magazine_” or “ kmem_va_”, the kmem_slab_cache, the kmem_bufctl_cache and others. In a 14 byte request,Two bytes of the resulting buffer are unused, since the request is satisfiedThe last set of caches are those used internally by the kernel memoryAllocator for its own bookkeeping.
0 Comments
Leave a Reply. |
AuthorMatt ArchivesCategories |