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Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 83 |
1 files changed, 72 insertions, 11 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 363e348bff9b..e567af39ee34 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -564,6 +564,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. UART at the specified I/O port or MMIO address, switching to the matching ttyS device later. The options are the same as for ttyS, above. + hvc<n> Use the hypervisor console device <n>. This is for + both Xen and PowerPC hypervisors. If the device connected to the port is not a TTY but a braille device, prepend "brl," before the device type, for instance @@ -594,6 +596,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. is selected automatically. Check Documentation/kdump/kdump.txt for further details. + crashkernel_low=size[KMG] + [KNL, x86] parts under 4G. + crashkernel=range1:size1[,range2:size2,...][@offset] [KNL] Same as above, but depends on the memory in the running system. The syntax of range is @@ -754,6 +759,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. earlyprintk= [X86,SH,BLACKFIN] earlyprintk=vga + earlyprintk=xen earlyprintk=serial[,ttySn[,baudrate]] earlyprintk=ttySn[,baudrate] earlyprintk=dbgp[debugController#] @@ -771,6 +777,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. The VGA output is eventually overwritten by the real console. + The xen output can only be used by Xen PV guests. + ekgdboc= [X86,KGDB] Allow early kernel console debugging ekgdboc=kbd @@ -1039,16 +1047,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Claim all unknown PCI IDE storage controllers. idle= [X86] - Format: idle=poll, idle=mwait, idle=halt, idle=nomwait + Format: idle=poll, idle=halt, idle=nomwait Poll forces a polling idle loop that can slightly improve the performance of waking up a idle CPU, but will use a lot of power and make the system run hot. Not recommended. - idle=mwait: On systems which support MONITOR/MWAIT but - the kernel chose to not use it because it doesn't save - as much power as a normal idle loop, use the - MONITOR/MWAIT idle loop anyways. Performance should be - the same as idle=poll. idle=halt: Halt is forced to be used for CPU idle. In such case C2/C3 won't be used again. idle=nomwait: Disable mwait for CPU C-states @@ -1131,6 +1134,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 0 disables intel_idle and fall back on acpi_idle. 1 to 6 specify maximum depth of C-state. + intel_pstate= [X86] + disable + Do not enable intel_pstate as the default + scaling driver for the supported processors + intremap= [X86-64, Intel-IOMMU] on enable Interrupt Remapping (default) off disable Interrupt Remapping @@ -1637,6 +1645,42 @@ bytes respectively. Such letter suffixes can also be entirely omitted. that the amount of memory usable for all allocations is not too small. + movablemem_map=acpi + [KNL,X86,IA-64,PPC] This parameter is similar to + memmap except it specifies the memory map of + ZONE_MOVABLE. + This option inform the kernel to use Hot Pluggable bit + in flags from SRAT from ACPI BIOS to determine which + memory devices could be hotplugged. The corresponding + memory ranges will be set as ZONE_MOVABLE. + NOTE: Whatever node the kernel resides in will always + be un-hotpluggable. + + movablemem_map=nn[KMG]@ss[KMG] + [KNL,X86,IA-64,PPC] This parameter is similar to + memmap except it specifies the memory map of + ZONE_MOVABLE. + If user specifies memory ranges, the info in SRAT will + be ingored. And it works like the following: + - If more ranges are all within one node, then from + lowest ss to the end of the node will be ZONE_MOVABLE. + - If a range is within a node, then from ss to the end + of the node will be ZONE_MOVABLE. + - If a range covers two or more nodes, then from ss to + the end of the 1st node will be ZONE_MOVABLE, and all + the rest nodes will only have ZONE_MOVABLE. + If memmap is specified at the same time, the + movablemem_map will be limited within the memmap + areas. If kernelcore or movablecore is also specified, + movablemem_map will have higher priority to be + satisfied. So the administrator should be careful that + the amount of movablemem_map areas are not too large. + Otherwise kernel won't have enough memory to start. + NOTE: We don't stop users specifying the node the + kernel resides in as hotpluggable so that this + option can be used as a workaround of firmware + bugs. + MTD_Partition= [MTD] Format: <name>,<region-number>,<size>,<offset> @@ -1886,10 +1930,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. wfi(ARM) instruction doesn't work correctly and not to use it. This is also useful when using JTAG debugger. - no-hlt [BUGS=X86-32] Tells the kernel that the hlt - instruction doesn't work correctly and not to - use it. - no_file_caps Tells the kernel not to honor file capabilities. The only way then for a file to be executed with privilege is to be setuid root or executed by root. @@ -2227,6 +2267,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted. This sorting is done to get a device order compatible with older (<= 2.4) kernels. nobfsort Don't sort PCI devices into breadth-first order. + pcie_bus_tune_off Disable PCIe MPS (Max Payload Size) + tuning and use the BIOS-configured MPS defaults. + pcie_bus_safe Set every device's MPS to the largest value + supported by all devices below the root complex. + pcie_bus_perf Set device MPS to the largest allowable MPS + based on its parent bus. Also set MRRS (Max + Read Request Size) to the largest supported + value (no larger than the MPS that the device + or bus can support) for best performance. + pcie_bus_peer2peer Set every device's MPS to 128B, which + every device is guaranteed to support. This + configuration allows peer-to-peer DMA between + any pair of devices, possibly at the cost of + reduced performance. This also guarantees + that hot-added devices will work. cbiosize=nn[KMG] The fixed amount of bus space which is reserved for the CardBus bridge's IO window. The default value is 256 bytes. @@ -2248,6 +2303,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. the default. off: Turn ECRC off on: Turn ECRC on. + hpiosize=nn[KMG] The fixed amount of bus space which is + reserved for hotplug bridge's IO window. + Default size is 256 bytes. + hpmemsize=nn[KMG] The fixed amount of bus space which is + reserved for hotplug bridge's memory window. + Default size is 2 megabytes. realloc= Enable/disable reallocating PCI bridge resources if allocations done by BIOS are too small to accommodate resources required by all child @@ -2438,7 +2499,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. real-time workloads. It can also improve energy efficiency for asymmetric multiprocessors. - rcu_nocbs_poll [KNL,BOOT] + rcu_nocb_poll [KNL,BOOT] Rather than requiring that offloaded CPUs (specified by rcu_nocbs= above) explicitly awaken the corresponding "rcuoN" kthreads, |