diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 158 |
1 files changed, 139 insertions, 19 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 8c18e7d98f8a..1169a4acfeb1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2627,14 +2627,14 @@ when set. Format: <int> - libata.force= [LIBATA] Force configurations. The format is comma- - separated list of "[ID:]VAL" where ID is - PORT[.DEVICE]. PORT and DEVICE are decimal numbers - matching port, link or device. Basically, it matches - the ATA ID string printed on console by libata. If - the whole ID part is omitted, the last PORT and DEVICE - values are used. If ID hasn't been specified yet, the - configuration applies to all ports, links and devices. + libata.force= [LIBATA] Force configurations. The format is a comma- + separated list of "[ID:]VAL" where ID is PORT[.DEVICE]. + PORT and DEVICE are decimal numbers matching port, link + or device. Basically, it matches the ATA ID string + printed on console by libata. If the whole ID part is + omitted, the last PORT and DEVICE values are used. If + ID hasn't been specified yet, the configuration applies + to all ports, links and devices. If only DEVICE is omitted, the parameter applies to the port and all links and devices behind it. DEVICE @@ -2644,7 +2644,7 @@ host link and device attached to it. The VAL specifies the configuration to force. As long - as there's no ambiguity shortcut notation is allowed. + as there is no ambiguity, shortcut notation is allowed. For example, both 1.5 and 1.5G would work for 1.5Gbps. The following configurations can be forced. @@ -2657,19 +2657,58 @@ udma[/][16,25,33,44,66,100,133] notation is also allowed. + * nohrst, nosrst, norst: suppress hard, soft and both + resets. + + * rstonce: only attempt one reset during hot-unplug + link recovery. + + * [no]dbdelay: Enable or disable the extra 200ms delay + before debouncing a link PHY and device presence + detection. + * [no]ncq: Turn on or off NCQ. - * [no]ncqtrim: Turn off queued DSM TRIM. + * [no]ncqtrim: Enable or disable queued DSM TRIM. + + * [no]ncqati: Enable or disable NCQ trim on ATI chipset. + + * [no]trim: Enable or disable (unqueued) TRIM. + + * trim_zero: Indicate that TRIM command zeroes data. + + * max_trim_128m: Set 128M maximum trim size limit. + + * [no]dma: Turn on or off DMA transfers. + + * atapi_dmadir: Enable ATAPI DMADIR bridge support. + + * atapi_mod16_dma: Enable the use of ATAPI DMA for + commands that are not a multiple of 16 bytes. + + * [no]dmalog: Enable or disable the use of the + READ LOG DMA EXT command to access logs. - * nohrst, nosrst, norst: suppress hard, soft - and both resets. + * [no]iddevlog: Enable or disable access to the + identify device data log. - * rstonce: only attempt one reset during - hot-unplug link recovery + * [no]logdir: Enable or disable access to the general + purpose log directory. - * dump_id: dump IDENTIFY data. + * max_sec_128: Set transfer size limit to 128 sectors. - * atapi_dmadir: Enable ATAPI DMADIR bridge support + * max_sec_1024: Set or clear transfer size limit to + 1024 sectors. + + * max_sec_lba48: Set or clear transfer size limit to + 65535 sectors. + + * [no]lpm: Enable or disable link power management. + + * [no]setxfer: Indicate if transfer speed mode setting + should be skipped. + + * dump_id: Dump IDENTIFY data. * disable: Disable this device. @@ -4889,6 +4928,18 @@ rcupdate.rcu_cpu_stall_timeout= [KNL] Set timeout for RCU CPU stall warning messages. + The value is in seconds and the maximum allowed + value is 300 seconds. + + rcupdate.rcu_exp_cpu_stall_timeout= [KNL] + Set timeout for expedited RCU CPU stall warning + messages. The value is in milliseconds + and the maximum allowed value is 21000 + milliseconds. Please note that this value is + adjusted to an arch timer tick resolution. + Setting this to zero causes the value from + rcupdate.rcu_cpu_stall_timeout to be used (after + conversion from seconds to milliseconds). rcupdate.rcu_expedited= [KNL] Use expedited grace-period primitives, for @@ -4951,10 +5002,34 @@ number avoids disturbing real-time workloads, but lengthens grace periods. + rcupdate.rcu_task_stall_info= [KNL] + Set initial timeout in jiffies for RCU task stall + informational messages, which give some indication + of the problem for those not patient enough to + wait for ten minutes. Informational messages are + only printed prior to the stall-warning message + for a given grace period. Disable with a value + less than or equal to zero. Defaults to ten + seconds. A change in value does not take effect + until the beginning of the next grace period. + + rcupdate.rcu_task_stall_info_mult= [KNL] + Multiplier for time interval between successive + RCU task stall informational messages for a given + RCU tasks grace period. This value is clamped + to one through ten, inclusive. It defaults to + the value three, so that the first informational + message is printed 10 seconds into the grace + period, the second at 40 seconds, the third at + 160 seconds, and then the stall warning at 600 + seconds would prevent a fourth at 640 seconds. + 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. + Set timeout in jiffies for RCU task stall + warning messages. Disable with a value less + than or equal to zero. Defaults to ten minutes. + A change in value does not take effect until + the beginning of the next grace period. rcupdate.rcu_self_test= [KNL] Run the RCU early boot self tests @@ -5304,6 +5379,8 @@ serialnumber [BUGS=X86-32] + sev=option[,option...] [X86-64] See Documentation/x86/x86_64/boot-options.rst + shapers= [NET] Maximal number of shapers. @@ -5373,6 +5450,17 @@ smart2= [HW] Format: <io1>[,<io2>[,...,<io8>]] + smp.csd_lock_timeout= [KNL] + Specify the period of time in milliseconds + that smp_call_function() and friends will wait + for a CPU to release the CSD lock. This is + useful when diagnosing bugs involving CPUs + disabling interrupts for extended periods + of time. Defaults to 5,000 milliseconds, and + setting a value of zero disables this feature. + This feature may be more efficiently disabled + using the csdlock_debug- kernel parameter. + smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port smsc-ircc2.ircc_sir= [HW] SIR base I/O port @@ -5604,6 +5692,30 @@ off: Disable mitigation and remove performance impact to RDRAND and RDSEED + srcutree.big_cpu_lim [KNL] + Specifies the number of CPUs constituting a + large system, such that srcu_struct structures + should immediately allocate an srcu_node array. + This kernel-boot parameter defaults to 128, + but takes effect only when the low-order four + bits of srcutree.convert_to_big is equal to 3 + (decide at boot). + + srcutree.convert_to_big [KNL] + Specifies under what conditions an SRCU tree + srcu_struct structure will be converted to big + form, that is, with an rcu_node tree: + + 0: Never. + 1: At init_srcu_struct() time. + 2: When rcutorture decides to. + 3: Decide at boot time (default). + 0x1X: Above plus if high contention. + + Either way, the srcu_node tree will be sized based + on the actual runtime number of CPUs (nr_cpu_ids) + instead of the compile-time CONFIG_NR_CPUS. + srcutree.counter_wrap_check [KNL] Specifies how frequently to check for grace-period sequence counter wrap for the @@ -5621,6 +5733,14 @@ expediting. Set to zero to disable automatic expediting. + srcutree.small_contention_lim [KNL] + Specifies the number of update-side contention + events per jiffy will be tolerated before + initiating a conversion of an srcu_struct + structure to big form. Note that the value of + srcutree.convert_to_big must have the 0x10 bit + set for contention-based conversions to occur. + ssbd= [ARM64,HW] Speculative Store Bypass Disable control |