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Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 204 |
1 files changed, 182 insertions, 22 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 883901b9ac4f..479f33204a37 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -571,6 +571,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. trust validation. format: { id:<keyid> | builtin } + cca= [MIPS] Override the kernel pages' cache coherency + algorithm. Accepted values range from 0 to 7 + inclusive. See arch/mips/include/asm/pgtable-bits.h + for platform specific values (SB1, Loongson3 and + others). + ccw_timeout_log [S390] See Documentation/s390/CommonIO for details. @@ -599,11 +605,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. See Documentation/s390/CommonIO for details. clk_ignore_unused [CLK] - Keep all clocks already enabled by bootloader on, - even if no driver has claimed them. This is useful - for debug and development, but should not be - needed on a platform with proper driver support. - For more information, see Documentation/clk.txt. + Prevents the clock framework from automatically gating + clocks that have not been explicitly enabled by a Linux + device driver but are enabled in hardware at reset or + by the bootloader/firmware. Note that this does not + force such clocks to be always-on nor does it reserve + those clocks in any way. This parameter is useful for + debug and development, but should not be needed on a + platform with proper driver support. For more + information, see Documentation/clk.txt. clock= [BUGS=X86-32, HW] gettimeofday clocksource override. [Deprecated] @@ -650,7 +660,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Sets the size of kernel global memory area for contiguous memory allocations and optionally the placement constraint by the physical address range of - memory allocations. For more information, see + memory allocations. A value of 0 disables CMA + altogether. For more information, see include/linux/dma-contiguous.h cmo_free_hint= [PPC] Format: { yes | no } @@ -915,6 +926,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. earlycon= [KNL] Output early console device and options. + cdns,<addr> + Start an early, polled-mode console on a cadence serial + port at the specified address. The cadence serial port + must already be setup and configured. Options are not + yet supported. + uart[8250],io,<addr>[,options] uart[8250],mmio,<addr>[,options] uart[8250],mmio32,<addr>[,options] @@ -930,6 +947,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted. must already be setup and configured. Options are not yet supported. + msm_serial,<addr> + Start an early, polled-mode console on an msm serial + port at the specified address. The serial port + must already be setup and configured. Options are not + yet supported. + + msm_serial_dm,<addr> + Start an early, polled-mode console on an msm serial + dm port at the specified address. The serial port + must already be setup and configured. Options are not + yet supported. + smh Use ARM semihosting calls for early console. earlyprintk= [X86,SH,BLACKFIN,ARM,M68k] @@ -986,10 +1015,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Format: {"off" | "on" | "skip[mbr]"} efi= [EFI] - Format: { "old_map" } + Format: { "old_map", "nochunk", "noruntime" } old_map [X86-64]: switch to the old ioremap-based EFI runtime services mapping. 32-bit still uses this one by default. + nochunk: disable reading files in "chunks" in the EFI + boot stub, as chunking can cause problems with some + firmware implementations. + noruntime : disable EFI runtime services support efi_no_storage_paranoia [EFI; X86] Using this parameter you can use more than 50% of @@ -1274,6 +1307,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted. .cdrom .chs .ignore_cable are additional options See Documentation/ide/ide.txt. + ide-generic.probe-mask= [HW] (E)IDE subsystem + Format: <int> + Probe mask for legacy ISA IDE ports. Depending on + platform up to 6 ports are supported, enabled by + setting corresponding bits in the mask to 1. The + default value is 0x0, which has a special meaning. + On systems that have PCI, it triggers scanning the + PCI bus for the first and the second port, which + are then probed. On systems without PCI the value + of 0x0 enables probing the two first ports as if it + was 0x3. + ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem Claim all unknown PCI IDE storage controllers. @@ -1298,7 +1343,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Set number of hash buckets for inode cache. ima_appraise= [IMA] appraise integrity measurements - Format: { "off" | "enforce" | "fix" } + Format: { "off" | "enforce" | "fix" | "log" } default: "enforce" ima_appraise_tcb [IMA] @@ -1554,6 +1599,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. kmemleak= [KNL] Boot-time kmemleak enable/disable Valid arguments: on, off Default: on + Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y, + the default is off. kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode Valid arguments: 0, 1, 2 @@ -1698,6 +1745,49 @@ bytes respectively. Such letter suffixes can also be entirely omitted. lockd.nlm_udpport=M [NFS] Assign UDP port. Format: <integer> + locktorture.nreaders_stress= [KNL] + Set the number of locking read-acquisition kthreads. + Defaults to being automatically set based on the + number of online CPUs. + + locktorture.nwriters_stress= [KNL] + Set the number of locking write-acquisition kthreads. + + locktorture.onoff_holdoff= [KNL] + Set time (s) after boot for CPU-hotplug testing. + + locktorture.onoff_interval= [KNL] + Set time (s) between CPU-hotplug operations, or + zero to disable CPU-hotplug testing. + + locktorture.shuffle_interval= [KNL] + Set task-shuffle interval (jiffies). Shuffling + tasks allows some CPUs to go into dyntick-idle + mode during the locktorture test. + + locktorture.shutdown_secs= [KNL] + Set time (s) after boot system shutdown. This + is useful for hands-off automated testing. + + locktorture.stat_interval= [KNL] + Time (s) between statistics printk()s. + + locktorture.stutter= [KNL] + 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 the locking primitive's ability to + transition abruptly to and from idle. + + locktorture.torture_runnable= [BOOT] + Start locktorture running at boot time. + + locktorture.torture_type= [KNL] + Specify the locking implementation to test. + + locktorture.verbose= [KNL] + Enable additional printk() statements. + logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver Format: <irq> @@ -1716,8 +1806,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 7 (KERN_DEBUG) debug-level messages log_buf_len=n[KMG] Sets the size of the printk ring buffer, - in bytes. n must be a power of two. The default - size is set in the kernel config file. + in bytes. n must be a power of two and greater + than the minimal size. The minimal size is defined + by LOG_BUF_SHIFT kernel config parameter. There is + also CONFIG_LOG_CPU_MAX_BUF_SHIFT config parameter + that allows to increase the default size depending on + the number of CPUs. See init/Kconfig for more details. logo.nologo [FB] Disables display of the built-in Linux logo. This may be used to provide more screen space for @@ -2156,7 +2250,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nodsp [SH] Disable hardware DSP at boot time. - noefi [X86] Disable EFI runtime services support. + noefi Disable EFI runtime services support. noexec [IA-64] @@ -2190,6 +2284,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted. and restore using xsave. The kernel will fallback to enabling legacy floating-point and sse state. + noxsaveopt [X86] Disables xsaveopt used in saving x86 extended + register states. The kernel will fall back to use + xsave to save the states. By using this parameter, + performance of saving the states is degraded because + xsave doesn't support modified optimization while + xsaveopt supports it on xsaveopt enabled systems. + + noxsaves [X86] Disables xsaves and xrstors used in saving and + restoring x86 extended register state in compacted + form of xsave area. The kernel will fall back to use + xsaveopt and xrstor to save and restore the states + in standard form of xsave area. By using this + parameter, xsave area per process might occupy more + memory on xsaves enabled systems. + eagerfpu= [X86] on enable eager fpu restore off disable eager fpu restore @@ -2856,6 +2965,24 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Lazy RCU callbacks are those which RCU can prove do nothing more than free memory. + rcutorture.cbflood_inter_holdoff= [KNL] + Set holdoff time (jiffies) between successive + callback-flood tests. + + rcutorture.cbflood_intra_holdoff= [KNL] + Set holdoff time (jiffies) between successive + bursts of callbacks within a given callback-flood + test. + + rcutorture.cbflood_n_burst= [KNL] + Set the number of bursts making up a given + callback-flood test. Set this to zero to + disable callback-flood testing. + + rcutorture.cbflood_n_per_burst= [KNL] + Set the number of callbacks to be registered + in a given burst of a callback-flood test. + rcutorture.fqs_duration= [KNL] Set duration of force_quiescent_state bursts. @@ -2895,7 +3022,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Set time (s) between CPU-hotplug operations, or zero to disable CPU-hotplug testing. - rcutorture.rcutorture_runnable= [BOOT] + rcutorture.torture_runnable= [BOOT] Start rcutorture running at boot time. rcutorture.shuffle_interval= [KNL] @@ -2957,6 +3084,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. rcupdate.rcu_cpu_stall_timeout= [KNL] Set timeout for RCU CPU stall warning messages. + rcupdate.rcu_task_stall_timeout= [KNL] + Set timeout in jiffies for RCU task stall warning + messages. Disable with a value less than or equal + to zero. + rdinit= [KNL] Format: <full_path> Run specified binary instead of /init from the ramdisk, @@ -3054,6 +3186,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. S [KNL] Run init in single mode + s390_iommu= [HW,S390] + Set s390 IOTLB flushing mode + strict + With strict flushing every unmap operation will result in + an IOTLB flush. Default is lazy flushing before reuse, + which is faster. + sa1100ir [NET] See drivers/net/irda/sa1100_ir.c. @@ -3108,6 +3247,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. slram= [HW,MTD] + slab_nomerge [MM] + Disable merging of slabs with similar size. May be + necessary if there is some reason to distinguish + allocs to different slabs. Debug options disable + merging on their own. + For more information see Documentation/vm/slub.txt. + slab_max_order= [MM, SLAB] Determines the maximum allowed order for slabs. A high setting may cause OOMs due to memory @@ -3143,11 +3289,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. For more information see Documentation/vm/slub.txt. slub_nomerge [MM, SLUB] - Disable merging of slabs with similar size. May be - necessary if there is some reason to distinguish - allocs to different slabs. Debug options disable - merging on their own. - For more information see Documentation/vm/slub.txt. + Same with slab_nomerge. This is supported for legacy. + See slab_nomerge for more information. smart2= [HW] Format: <io1>[,<io2>[,...,<io8>]] @@ -3271,11 +3414,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. tdfx= [HW,DRM] - test_suspend= [SUSPEND] + test_suspend= [SUSPEND][,N] Specify "mem" (for Suspend-to-RAM) or "standby" (for - standby suspend) as the system sleep state to briefly - enter during system startup. The system is woken from - this state using a wakeup-capable RTC alarm. + standby suspend) or "freeze" (for suspend type freeze) + as the system sleep state during system startup with + the optional capability to repeat N number of times. + The system is woken from this state using a + wakeup-capable RTC alarm. thash_entries= [KNL,NET] Set number of hash buckets for TCP connection @@ -3338,6 +3483,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. e.g. base its process migration decisions on it. Default is on. + topology_updates= [KNL, PPC, NUMA] + Format: {off} + Specify if the kernel should ignore (off) + topology updates sent by the hypervisor to this + LPAR. + tp720= [HW,PS2] tpm_suspend_pcr=[HW,TPM] @@ -3470,7 +3621,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. usb-storage.delay_use= [UMS] The delay in seconds before a new device is - scanned for Logical Units (default 5). + scanned for Logical Units (default 1). usb-storage.quirks= [UMS] A list of quirks entries to supplement or @@ -3490,6 +3641,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. READ_DISC_INFO command); e = NO_READ_CAPACITY_16 (don't use READ_CAPACITY_16 command); + f = NO_REPORT_OPCODES (don't use report opcodes + command, uas only); h = CAPACITY_HEURISTICS (decrease the reported device capacity by one sector if the number is odd); @@ -3509,6 +3662,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. bogus residue values); s = SINGLE_LUN (the device has only one Logical Unit); + t = NO_ATA_1X (don't allow ATA(12) and ATA(16) + commands, uas only); + u = IGNORE_UAS (don't bind to the uas driver); w = NO_WP_DETECT (don't test whether the medium is write-protected). Example: quirks=0419:aaf5:rl,0421:0433:rc @@ -3728,6 +3884,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Disables the ticketlock slowpath using Xen PV optimizations. + xen_nopv [X86] + Disables the PV optimizations forcing the HVM guest to + run as generic HVM guest with no PV drivers. + xirc2ps_cs= [NET,PCMCIA] Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] |