diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 63 |
1 files changed, 55 insertions, 8 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 0d97f811d8b1..76e538c77e31 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1407,14 +1407,21 @@ earlyprintk=serial[,0x...[,baudrate]] earlyprintk=ttySn[,baudrate] earlyprintk=dbgp[debugController#] - earlyprintk=pciserial[,force],bus:device.function[,baudrate] + earlyprintk=pciserial[,force],bus:device.function[,{nocfg|baudrate}] earlyprintk=xdbc[xhciController#] earlyprintk=bios + earlyprintk=mmio,membase[,{nocfg|baudrate}] earlyprintk is useful when the kernel crashes before the normal console is initialized. It is not enabled by default because it has some cosmetic problems. + Only 32-bit memory addresses are supported for "mmio" + and "pciserial" devices. + + Use "nocfg" to skip UART configuration, assume + BIOS/firmware has configured UART correctly. + Append ",keep" to not disable it when the real console takes over. @@ -1859,7 +1866,7 @@ hpet_mmap= [X86, HPET_MMAP] Allow userspace to mmap HPET registers. Default set by CONFIG_HPET_MMAP_DEFAULT. - hugepages= [HW] Number of HugeTLB pages to allocate at boot. + hugepages= [HW,EARLY] Number of HugeTLB pages to allocate at boot. If this follows hugepagesz (below), it specifies the number of pages of hugepagesz to be allocated. If this is the first HugeTLB parameter on the command @@ -1871,15 +1878,24 @@ <node>:<integer>[,<node>:<integer>] hugepagesz= - [HW] The size of the HugeTLB pages. This is used in - conjunction with hugepages (above) to allocate huge - pages of a specific size at boot. The pair - hugepagesz=X hugepages=Y can be specified once for - each supported huge page size. Huge page sizes are - architecture dependent. See also + [HW,EARLY] The size of the HugeTLB pages. This is + used in conjunction with hugepages (above) to + allocate huge pages of a specific size at boot. The + pair hugepagesz=X hugepages=Y can be specified once + for each supported huge page size. Huge page sizes + are architecture dependent. See also Documentation/admin-guide/mm/hugetlbpage.rst. Format: size[KMG] + hugepage_alloc_threads= + [HW] The number of threads that should be used to + allocate hugepages during boot. This option can be + used to improve system bootup time when allocating + a large amount of huge pages. + The default value is 25% of the available hardware threads. + + Note that this parameter only applies to non-gigantic huge pages. + hugetlb_cma= [HW,CMA,EARLY] The size of a CMA area used for allocation of gigantic hugepages. Or using node format, the size of a CMA area per node can be specified. @@ -1890,6 +1906,13 @@ hugepages using the CMA allocator. If enabled, the boot-time allocation of gigantic hugepages is skipped. + hugetlb_cma_only= + [HW,CMA,EARLY] When allocating new HugeTLB pages, only + try to allocate from the CMA areas. + + This option does nothing if hugetlb_cma= is not also + specified. + hugetlb_free_vmemmap= [KNL] Requires CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP enabled. @@ -1931,6 +1954,12 @@ which allow the hypervisor to 'idle' the guest on lock contention. + hw_protection= [HW] + Format: reboot | shutdown + + Hardware protection action taken on critical events like + overtemperature or imminent voltage loss. + i2c_bus= [HW] Override the default board specific I2C bus speed or register an additional I2C bus that is not registered from board initialization code. @@ -7259,6 +7288,8 @@ This is just one of many ways that can clear memory. Make sure your system keeps the content of memory across reboots before relying on this option. + NB: Both the mapped address and size must be page aligned for the architecture. + See also Documentation/trace/debugging.rst @@ -7504,6 +7535,22 @@ Note that genuine overcurrent events won't be reported either. + unaligned_scalar_speed= + [RISCV] + Format: {slow | fast | unsupported} + Allow skipping scalar unaligned access speed tests. This + is useful for testing alternative code paths and to skip + the tests in environments where they run too slowly. All + CPUs must have the same scalar unaligned access speed. + + unaligned_vector_speed= + [RISCV] + Format: {slow | fast | unsupported} + Allow skipping vector unaligned access speed tests. This + is useful for testing alternative code paths and to skip + the tests in environments where they run too slowly. All + CPUs must have the same vector unaligned access speed. + unknown_nmi_panic [X86] Cause panic on unknown NMI. |