diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 78 |
1 files changed, 69 insertions, 9 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2dda5ada4e1a..0081d83457e8 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -113,7 +113,7 @@ the GPE dispatcher. This facility can be used to prevent such uncontrolled GPE floodings. - Format: <byte> + Format: <byte> or <bitmap-list> acpi_no_auto_serialize [HW,ACPI] Disable auto-serialization of AML methods @@ -500,16 +500,21 @@ ccw_timeout_log [S390] See Documentation/s390/common_io.rst for details. - cgroup_disable= [KNL] Disable a particular controller - Format: {name of the controller(s) to disable} + cgroup_disable= [KNL] Disable a particular controller or optional feature + Format: {name of the controller(s) or feature(s) to disable} The effects of cgroup_disable=foo are: - foo isn't auto-mounted if you mount all cgroups in a single hierarchy - foo isn't visible as an individually mountable subsystem + - if foo is an optional feature then the feature is + disabled and corresponding cgroup files are not + created {Currently only "memory" controller deal with this and cut the overhead, others just disable the usage. So only cgroup_disable=memory is actually worthy} + Specifying "pressure" disables per-cgroup pressure + stall information accounting feature cgroup_no_v1= [KNL] Disable cgroup controllers and named hierarchies in v1 Format: { { controller | "all" | "named" } @@ -584,6 +589,28 @@ loops can be debugged more effectively on production systems. + clocksource.max_cswd_read_retries= [KNL] + Number of clocksource_watchdog() retries due to + external delays before the clock will be marked + unstable. Defaults to three retries, that is, + four attempts to read the clock under test. + + clocksource.verify_n_cpus= [KNL] + Limit the number of CPUs checked for clocksources + marked with CLOCK_SOURCE_VERIFY_PERCPU that + are marked unstable due to excessive skew. + A negative value says to check all CPUs, while + zero says not to check any. Values larger than + nr_cpu_ids are silently truncated to nr_cpu_ids. + The actual CPUs are chosen randomly, with + no replacement if the same CPU is chosen twice. + + clocksource-wdtest.holdoff= [KNL] + Set the time in seconds that the clocksource + watchdog test waits before commencing its tests. + Defaults to zero when built as a module and to + 10 seconds when built into the kernel. + clearcpuid=BITNUM[,BITNUM...] [X86] Disable CPUID feature X for the kernel. See arch/x86/include/asm/cpufeatures.h for the valid bit @@ -1570,6 +1597,23 @@ Documentation/admin-guide/mm/hugetlbpage.rst. Format: size[KMG] + hugetlb_free_vmemmap= + [KNL] Reguires CONFIG_HUGETLB_PAGE_FREE_VMEMMAP + enabled. + Allows heavy hugetlb users to free up some more + memory (6 * PAGE_SIZE for each 2MB hugetlb page). + Format: { on | off (default) } + + on: enable the feature + off: disable the feature + + Built with CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON=y, + the default is on. + + This is not compatible with memory_hotplug.memmap_on_memory. + If both parameters are enabled, hugetlb_free_vmemmap takes + precedence over memory_hotplug.memmap_on_memory. + hung_task_panic= [KNL] Should the hung task detector generate panics. Format: 0 | 1 @@ -2840,6 +2884,10 @@ Note that even when enabled, there are a few cases where the feature is not effective. + This is not compatible with hugetlb_free_vmemmap. If + both parameters are enabled, hugetlb_free_vmemmap takes + precedence over memory_hotplug.memmap_on_memory. + memtest= [KNL,X86,ARM,PPC,RISCV] Enable memtest Format: <integer> default : 0 <disable> @@ -3251,7 +3299,7 @@ noclflush [BUGS=X86] Don't use the CLFLUSH instruction - nodelayacct [KNL] Disable per-task delay accounting + delayacct [KNL] Enable per-task delay accounting nodsp [SH] Disable hardware DSP at boot time. @@ -3520,6 +3568,9 @@ nr_uarts= [SERIAL] maximum number of UARTs to be registered. + numa=off [KNL, ARM64, PPC, RISCV, SPARC, X86] Disable NUMA, Only + set up a single NUMA node spanning all memory. + numa_balancing= [KNL,ARM64,PPC,RISCV,S390,X86] Enable or disable automatic NUMA balancing. Allowed values are enable and disable @@ -3573,6 +3624,12 @@ off: turn off poisoning (default) on: turn on poisoning + page_reporting.page_reporting_order= + [KNL] Minimal page reporting order + Format: <integer> + Adjust the minimal page reporting order. The page + reporting is disabled when it exceeds (MAX_ORDER-1). + panic= [KNL] Kernel behaviour on panic: delay <timeout> timeout > 0: seconds before rebooting timeout = 0: wait forever @@ -4782,11 +4839,6 @@ Reserves a hole at the top of the kernel virtual address space. - reservelow= [X86] - Format: nn[K] - Set the amount of memory to reserve for BIOS at - the bottom of the address space. - reset_devices [KNL] Force drivers to reset the underlying device during initialization. @@ -5290,6 +5342,14 @@ exception. Default behavior is by #AC if both features are enabled in hardware. + ratelimit:N - + Set system wide rate limit to N bus locks + per second for bus lock detection. + 0 < N <= 1000. + + N/A for split lock detection. + + If an #AC exception is hit in the kernel or in firmware (i.e. not while executing in user mode) the kernel will oops in either "warn" or "fatal" |