diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 86 |
1 files changed, 70 insertions, 16 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 4c1971960afa..c7ac2f3ac99f 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -809,6 +809,8 @@ enables the feature at boot time. By default, it is disabled and the system will work mostly the same as a kernel built without CONFIG_DEBUG_PAGEALLOC. + Note: to get most of debug_pagealloc error reports, it's + useful to also enable the page_owner functionality. on: enable the feature debugpat [X86] Enable PAT debugging @@ -860,6 +862,10 @@ disable_radix [PPC] Disable RADIX MMU mode on POWER9 + disable_tlbie [PPC] + Disable TLBIE instruction. Currently does not work + with KVM, with HASH MMU, or with coherent accelerators. + disable_cpu_apicid= [X86,APIC,SMP] Format: <int> The number of initial APIC ID for the @@ -1044,6 +1050,10 @@ specified address. The serial port must already be setup and configured. Options are not yet supported. + sbi + Use RISC-V SBI (Supervisor Binary Interface) for early + console. + smh Use ARM semihosting calls for early console. s3c2410,<addr> @@ -1090,6 +1100,12 @@ the framebuffer, pass the 'ram' option so that it is mapped with the correct attributes. + linflex,<addr> + Use early console provided by Freescale LinFlex UART + serial driver for NXP S32V234 SoCs. A valid base + address must be provided, and the serial port must + already be setup and configured. + earlyprintk= [X86,SH,ARM,M68k,S390] earlyprintk=vga earlyprintk=sclp @@ -1197,12 +1213,6 @@ See comment before function elanfreq_setup() in arch/x86/kernel/cpu/cpufreq/elanfreq.c. - elevator= [IOSCHED] - Format: { "mq-deadline" | "kyber" | "bfq" } - See Documentation/block/deadline-iosched.rst, - Documentation/block/kyber-iosched.rst and - Documentation/block/bfq-iosched.rst for details. - elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] Specifies physical address of start of kernel core image elf header and optionally the size. Generally @@ -1732,6 +1742,11 @@ Note that using this option lowers the security provided by tboot because it makes the system vulnerable to DMA attacks. + nobounce [Default off] + Disable bounce buffer for unstrusted devices such as + the Thunderbolt devices. This will treat the untrusted + devices as the trusted ones, hence might expose security + risks of DMA attacks. intel_idle.max_cstate= [KNL,HW,ACPI,X86] 0 disables intel_idle and fall back on acpi_idle. @@ -1811,7 +1826,7 @@ synchronously. iommu.passthrough= - [ARM64] Configure DMA to bypass the IOMMU by default. + [ARM64, X86] Configure DMA to bypass the IOMMU by default. Format: { "0" | "1" } 0 - Use IOMMU translation for DMA. 1 - Bypass the IOMMU for DMA. @@ -2261,6 +2276,15 @@ lockd.nlm_udpport=M [NFS] Assign UDP port. Format: <integer> + lockdown= [SECURITY] + { integrity | confidentiality } + Enable the kernel lockdown feature. If set to + integrity, kernel features that allow userland to + modify the running kernel are disabled. If set to + confidentiality, kernel features that allow userland + to extract confidential information from the kernel + are also disabled. + locktorture.nreaders_stress= [KNL] Set the number of locking read-acquisition kthreads. Defaults to being automatically set based on the @@ -2373,7 +2397,7 @@ machvec= [IA-64] Force the use of a particular machine-vector (machvec) in a generic kernel. - Example: machvec=hpzx1_swiotlb + Example: machvec=hpzx1 machtype= [Loongson] Share the same kernel image file between different yeeloong laptop. @@ -3452,12 +3476,13 @@ specify the device is described above. If <order of align> is not specified, PAGE_SIZE is used as alignment. - PCI-PCI bridge can be specified, if resource + A PCI-PCI bridge can be specified if resource windows need to be expanded. To specify the alignment for several instances of a device, the PCI vendor, device, subvendor, and subdevice may be - specified, e.g., 4096@pci:8086:9c22:103c:198f + specified, e.g., 12@pci:8086:9c22:103c:198f + for 4096-byte alignment. ecrc= Enable/disable PCIe ECRC (transaction layer end-to-end CRC checking). bios: Use BIOS/firmware settings. This is the @@ -3837,12 +3862,13 @@ RCU_BOOST is not set, valid values are 0-99 and the default is zero (non-realtime operation). - rcutree.rcu_nocb_leader_stride= [KNL] - Set the number of NOCB kthread groups, which - defaults to the square root of the number of - CPUs. Larger numbers reduces the wakeup overhead - on the per-CPU grace-period kthreads, but increases - that same overhead on each group's leader. + rcutree.rcu_nocb_gp_stride= [KNL] + Set the number of NOCB callback kthreads in + each group, which defaults to the square root + of the number of CPUs. Larger numbers reduce + the wakeup overhead on the global grace-period + kthread, but increases that same overhead on + each group's NOCB grace-period kthread. rcutree.qhimark= [KNL] Set threshold of queued RCU callbacks beyond which @@ -4047,6 +4073,10 @@ rcutorture.verbose= [KNL] Enable additional printk() statements. + rcupdate.rcu_cpu_stall_ftrace_dump= [KNL] + Dump ftrace buffer after reporting RCU CPU + stall warning. + rcupdate.rcu_cpu_stall_suppress= [KNL] Suppress RCU CPU stall warning messages. @@ -4627,6 +4657,11 @@ /sys/power/pm_test). Only available when CONFIG_PM_DEBUG is set. Default value is 5. + svm= [PPC] + Format: { on | off | y | n | 1 | 0 } + This parameter controls use of the Protected + Execution Facility on pSeries. + swapaccount=[0|1] [KNL] Enable accounting of swap in memory resource controller if no parameter or 1 is given or disable @@ -5312,3 +5347,22 @@ A hex value specifying bitmask with supplemental xhci host controller quirks. Meaning of each bit can be consulted in header drivers/usb/host/xhci.h. + + xmon [PPC] + Format: { early | on | rw | ro | off } + Controls if xmon debugger is enabled. Default is off. + Passing only "xmon" is equivalent to "xmon=early". + early Call xmon as early as possible on boot; xmon + debugger is called from setup_arch(). + on xmon debugger hooks will be installed so xmon + is only called on a kernel crash. Default mode, + i.e. either "ro" or "rw" mode, is controlled + with CONFIG_XMON_DEFAULT_RO_MODE. + rw xmon debugger hooks will be installed so xmon + is called only on a kernel crash, mode is write, + meaning SPR registers, memory and, other data + can be written using xmon commands. + ro same as "rw" option above but SPR registers, + memory, and other data can't be written using + xmon commands. + off xmon is disabled. |