|
994 | 994 | 0: to disable low allocation. |
995 | 995 | It will be ignored when crashkernel=X,high is not used |
996 | 996 | or memory reserved is below 4G. |
| 997 | + crashkernel=size[KMG],cma |
| 998 | + [KNL, X86] Reserve additional crash kernel memory from |
| 999 | + CMA. This reservation is usable by the first system's |
| 1000 | + userspace memory and kernel movable allocations (memory |
| 1001 | + balloon, zswap). Pages allocated from this memory range |
| 1002 | + will not be included in the vmcore so this should not |
| 1003 | + be used if dumping of userspace memory is intended and |
| 1004 | + it has to be expected that some movable kernel pages |
| 1005 | + may be missing from the dump. |
| 1006 | + |
| 1007 | + A standard crashkernel reservation, as described above, |
| 1008 | + is still needed to hold the crash kernel and initrd. |
| 1009 | + |
| 1010 | + This option increases the risk of a kdump failure: DMA |
| 1011 | + transfers configured by the first kernel may end up |
| 1012 | + corrupting the second kernel's memory. |
| 1013 | + |
| 1014 | + This reservation method is intended for systems that |
| 1015 | + can't afford to sacrifice enough memory for standard |
| 1016 | + crashkernel reservation and where less reliable and |
| 1017 | + possibly incomplete kdump is preferable to no kdump at |
| 1018 | + all. |
997 | 1019 |
|
998 | 1020 | cryptomgr.notests |
999 | 1021 | [KNL] Disable crypto self-tests |
|
1806 | 1828 | backtraces on all cpus. |
1807 | 1829 | Format: 0 | 1 |
1808 | 1830 |
|
| 1831 | + hash_pointers= |
| 1832 | + [KNL,EARLY] |
| 1833 | + By default, when pointers are printed to the console |
| 1834 | + or buffers via the %p format string, that pointer is |
| 1835 | + "hashed", i.e. obscured by hashing the pointer value. |
| 1836 | + This is a security feature that hides actual kernel |
| 1837 | + addresses from unprivileged users, but it also makes |
| 1838 | + debugging the kernel more difficult since unequal |
| 1839 | + pointers can no longer be compared. The choices are: |
| 1840 | + Format: { auto | always | never } |
| 1841 | + Default: auto |
| 1842 | + |
| 1843 | + auto - Hash pointers unless slab_debug is enabled. |
| 1844 | + always - Always hash pointers (even if slab_debug is |
| 1845 | + enabled). |
| 1846 | + never - Never hash pointers. This option should only |
| 1847 | + be specified when debugging the kernel. Do |
| 1848 | + not use on production kernels. The boot |
| 1849 | + param "no_hash_pointers" is an alias for |
| 1850 | + this mode. |
| 1851 | + |
1809 | 1852 | hashdist= [KNL,NUMA] Large hashes allocated during boot |
1810 | 1853 | are distributed across NUMA nodes. Defaults on |
1811 | 1854 | for 64-bit NUMA, off otherwise. |
|
4194 | 4237 |
|
4195 | 4238 | no_hash_pointers |
4196 | 4239 | [KNL,EARLY] |
4197 | | - Force pointers printed to the console or buffers to be |
4198 | | - unhashed. By default, when a pointer is printed via %p |
4199 | | - format string, that pointer is "hashed", i.e. obscured |
4200 | | - by hashing the pointer value. This is a security feature |
4201 | | - that hides actual kernel addresses from unprivileged |
4202 | | - users, but it also makes debugging the kernel more |
4203 | | - difficult since unequal pointers can no longer be |
4204 | | - compared. However, if this command-line option is |
4205 | | - specified, then all normal pointers will have their true |
4206 | | - value printed. This option should only be specified when |
4207 | | - debugging the kernel. Please do not use on production |
4208 | | - kernels. |
| 4240 | + Alias for "hash_pointers=never". |
4209 | 4241 |
|
4210 | 4242 | nohibernate [HIBERNATION] Disable hibernation and resume. |
4211 | 4243 |
|
|
4557 | 4589 | bit 2: print timer info |
4558 | 4590 | bit 3: print locks info if CONFIG_LOCKDEP is on |
4559 | 4591 | bit 4: print ftrace buffer |
4560 | | - bit 5: print all printk messages in buffer |
| 4592 | + bit 5: replay all messages on consoles at the end of panic |
4561 | 4593 | bit 6: print all CPUs backtrace (if available in the arch) |
4562 | 4594 | bit 7: print only tasks in uninterruptible (blocked) state |
4563 | 4595 | *Be aware* that this option may print a _lot_ of lines, |
4564 | 4596 | so there are risks of losing older messages in the log. |
4565 | 4597 | Use this option carefully, maybe worth to setup a |
4566 | 4598 | bigger log buffer with "log_buf_len" along with this. |
4567 | 4599 |
|
| 4600 | + panic_sys_info= A comma separated list of extra information to be dumped |
| 4601 | + on panic. |
| 4602 | + Format: val[,val...] |
| 4603 | + Where @val can be any of the following: |
| 4604 | + |
| 4605 | + tasks: print all tasks info |
| 4606 | + mem: print system memory info |
| 4607 | + timers: print timers info |
| 4608 | + locks: print locks info if CONFIG_LOCKDEP is on |
| 4609 | + ftrace: print ftrace buffer |
| 4610 | + all_bt: print all CPUs backtrace (if available in the arch) |
| 4611 | + blocked_tasks: print only tasks in uninterruptible (blocked) state |
| 4612 | + |
| 4613 | + This is a human readable alternative to the 'panic_print' option. |
| 4614 | + |
| 4615 | + panic_console_replay |
| 4616 | + When panic happens, replay all kernel messages on |
| 4617 | + consoles at the end of panic. |
| 4618 | + |
4568 | 4619 | parkbd.port= [HW] Parallel port number the keyboard adapter is |
4569 | 4620 | connected to, default is 0. |
4570 | 4621 | Format: <parport#> |
|
6603 | 6654 | Documentation/admin-guide/mm/slab.rst. |
6604 | 6655 | (slub_debug legacy name also accepted for now) |
6605 | 6656 |
|
| 6657 | + Using this option implies the "no_hash_pointers" |
| 6658 | + option which can be undone by adding the |
| 6659 | + "hash_pointers=always" option. |
| 6660 | + |
6606 | 6661 | slab_max_order= [MM] |
6607 | 6662 | Determines the maximum allowed order for slabs. |
6608 | 6663 | A high setting may cause OOMs due to memory |
|
7032 | 7087 | consumed by the stack hash table. By default this is set |
7033 | 7088 | to false. |
7034 | 7089 |
|
| 7090 | + stack_depot_max_pools= [KNL,EARLY] |
| 7091 | + Specify the maximum number of pools to use for storing |
| 7092 | + stack traces. Pools are allocated on-demand up to this |
| 7093 | + limit. Default value is 8191 pools. |
| 7094 | + |
7035 | 7095 | stacktrace [FTRACE] |
7036 | 7096 | Enabled the stack tracer on boot up. |
7037 | 7097 |
|
|
0 commit comments