diff options
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 160 |
1 files changed, 151 insertions, 9 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c1601e5a8b71..a92c5ebf373e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -70,7 +70,6 @@ parameter is applicable: M68k M68k architecture is enabled. These options have more detailed description inside of Documentation/m68k/kernel-options.txt. - MCA MCA bus support is enabled. MDA MDA console support is enabled. MIPS MIPS architecture is enabled. MOUSE Appropriate mouse support is enabled. @@ -110,6 +109,7 @@ parameter is applicable: USB USB support is enabled. USBHID USB Human Interface Device support is enabled. V4L Video For Linux support is enabled. + VMMIO Driver for memory mapped virtio devices is enabled. VGA The VGA console has been enabled. VT Virtual terminal support is enabled. WDT Watchdog support is enabled. @@ -335,6 +335,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. requirements as needed. This option does not override iommu=pt + amd_iommu_dump= [HW,X86-64] + Enable AMD IOMMU driver option to dump the ACPI table + for AMD IOMMU. With this option enabled, AMD IOMMU + driver will print ACPI tables for AMD IOMMU during + IOMMU initialization. + amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: <a>,<b> @@ -397,8 +403,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. atkbd.softrepeat= [HW] Use software keyboard repeat - autotest [IA-64] - baycom_epp= [HW,AX25] Format: <io>,<mode> @@ -508,6 +512,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Also note the kernel might malfunction if you disable some critical bits. + cma=nn[MG] [ARM,KNL] + Sets the size of kernel global memory area for contiguous + memory allocations. For more information, see + include/linux/dma-contiguous.h + cmo_free_hint= [PPC] Format: { yes | no } Specify whether pages are marked as being inactive when they are freed. This is used in CMO environments @@ -515,6 +524,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. a hypervisor. Default: yes + coherent_pool=nn[KMG] [ARM,KNL] + Sets the size of memory pool for coherent, atomic dma + allocations if Contiguous Memory Allocator (CMA) is used. + code_bytes [X86] How many bytes of object code to print in an oops report. Range: 0 - 8192 @@ -610,7 +623,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot time. See Documentation/dynamic-debug-howto.txt for - details. + details. Deprecated, see dyndbg. debug [KNL] Enable kernel debugging (events log level). @@ -730,6 +743,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. dscc4.setup= [NET] + dyndbg[="val"] [KNL,DYNAMIC_DEBUG] + module.dyndbg[="val"] + Enable debug messages at boot time. See + Documentation/dynamic-debug-howto.txt for details. + earlycon= [KNL] Output early console device and options. uart[8250],io,<addr>[,options] uart[8250],mmio,<addr>[,options] @@ -982,6 +1000,20 @@ bytes respectively. Such letter suffixes can also be entirely omitted. i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN capability is set. + i915.invert_brightness= + [DRM] Invert the sense of the variable that is used to + set the brightness of the panel backlight. Normally a + brightness value of 0 indicates backlight switched off, + and the maximum of the brightness value sets the backlight + to maximum brightness. If this parameter is set to 0 + (default) and the machine requires it, or this parameter + is set to 1, a brightness value of 0 sets the backlight + to maximum brightness, and the maximum of the brightness + value switches the backlight off. + -1 -- never invert brightness + 0 -- machine default + 1 -- force brightness inversion + icn= [HW,ISDN] Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] @@ -1425,8 +1457,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. devices can be requested on-demand with the /dev/loop-control interface. - mcatest= [IA-64] - mce [X86-32] Machine Check Exception mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt @@ -2161,6 +2191,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. on: Turn realloc on realloc same as realloc=on noari do not use PCIe ARI. + pcie_scan_all Scan all possible PCIe devices. Otherwise we + only look for one device below a PCIe downstream + port. pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. @@ -2330,18 +2363,100 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ramdisk_size= [RAM] Sizes of RAM disks in kilobytes See Documentation/blockdev/ramdisk.txt. - rcupdate.blimit= [KNL,BOOT] + rcutree.blimit= [KNL,BOOT] Set maximum number of finished RCU callbacks to process in one batch. - rcupdate.qhimark= [KNL,BOOT] + rcutree.qhimark= [KNL,BOOT] Set threshold of queued RCU callbacks over which batch limiting is disabled. - rcupdate.qlowmark= [KNL,BOOT] + rcutree.qlowmark= [KNL,BOOT] Set threshold of queued RCU callbacks below which batch limiting is re-enabled. + rcutree.rcu_cpu_stall_suppress= [KNL,BOOT] + Suppress RCU CPU stall warning messages. + + rcutree.rcu_cpu_stall_timeout= [KNL,BOOT] + Set timeout for RCU CPU stall warning messages. + + rcutorture.fqs_duration= [KNL,BOOT] + Set duration of force_quiescent_state bursts. + + rcutorture.fqs_holdoff= [KNL,BOOT] + Set holdoff time within force_quiescent_state bursts. + + rcutorture.fqs_stutter= [KNL,BOOT] + Set wait time between force_quiescent_state bursts. + + rcutorture.irqreader= [KNL,BOOT] + Test RCU readers from irq handlers. + + rcutorture.n_barrier_cbs= [KNL,BOOT] + Set callbacks/threads for rcu_barrier() testing. + + rcutorture.nfakewriters= [KNL,BOOT] + Set number of concurrent RCU writers. These just + stress RCU, they don't participate in the actual + test, hence the "fake". + + rcutorture.nreaders= [KNL,BOOT] + Set number of RCU readers. + + rcutorture.onoff_holdoff= [KNL,BOOT] + Set time (s) after boot for CPU-hotplug testing. + + rcutorture.onoff_interval= [KNL,BOOT] + Set time (s) between CPU-hotplug operations, or + zero to disable CPU-hotplug testing. + + rcutorture.shuffle_interval= [KNL,BOOT] + Set task-shuffle interval (s). Shuffling tasks + allows some CPUs to go into dyntick-idle mode + during the rcutorture test. + + rcutorture.shutdown_secs= [KNL,BOOT] + Set time (s) after boot system shutdown. This + is useful for hands-off automated testing. + + rcutorture.stall_cpu= [KNL,BOOT] + Duration of CPU stall (s) to test RCU CPU stall + warnings, zero to disable. + + rcutorture.stall_cpu_holdoff= [KNL,BOOT] + Time to wait (s) after boot before inducing stall. + + rcutorture.stat_interval= [KNL,BOOT] + Time (s) between statistics printk()s. + + rcutorture.stutter= [KNL,BOOT] + Time (s) to stutter testing, for example, specifying + five seconds causes the test to run for five seconds, + wait for five seconds, and so on. This tests RCU's + ability to transition abruptly to and from idle. + + rcutorture.test_boost= [KNL,BOOT] + Test RCU priority boosting? 0=no, 1=maybe, 2=yes. + "Maybe" means test if the RCU implementation + under test support RCU priority boosting. + + rcutorture.test_boost_duration= [KNL,BOOT] + Duration (s) of each individual boost test. + + rcutorture.test_boost_interval= [KNL,BOOT] + Interval (s) between each boost test. + + rcutorture.test_no_idle_hz= [KNL,BOOT] + Test RCU's dyntick-idle handling. See also the + rcutorture.shuffle_interval parameter. + + rcutorture.torture_type= [KNL,BOOT] + Specify the RCU implementation to test. + + rcutorture.verbose= [KNL,BOOT] + Enable additional printk() statements. + rdinit= [KNL] Format: <full_path> Run specified binary instead of /init from the ramdisk, @@ -2372,6 +2487,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. resume= [SWSUSP] Specify the partition device for software suspend + Format: + {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>} resume_offset= [SWSUSP] Specify the offset from the beginning of the partition @@ -2426,6 +2543,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. sched_debug [KNL] Enables verbose scheduler debug messages. + skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate + xtime_lock contention on larger systems, and/or RCU lock + contention on all systems with CONFIG_MAXSMP set. + Format: { "0" | "1" } + 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1" + 1 -- enable. + Note: increases power consumption, thus should only be + enabled if running jitter sensitive (HPC/RT) workloads. + security= [SECURITY] Choose a security module to enable at boot. If this boot parameter is not specified, only the first security module asking for security registration will be @@ -2847,6 +2973,22 @@ bytes respectively. Such letter suffixes can also be entirely omitted. video= [FB] Frame buffer configuration See Documentation/fb/modedb.txt. + virtio_mmio.device= + [VMMIO] Memory mapped virtio (platform) device. + + <size>@<baseaddr>:<irq>[:<id>] + where: + <size> := size (can use standard suffixes + like K, M and G) + <baseaddr> := physical base address + <irq> := interrupt number (as passed to + request_irq()) + <id> := (optional) platform device id + example: + virtio_mmio.device=1K@0x100b0000:48:7 + + Can be used multiple times for multiple devices. + vga= [BOOT,X86-32] Select a particular video mode See Documentation/x86/boot.txt and Documentation/svga.txt. |