Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux
[linux-2.6-block.git] / Documentation / kernel-parameters.txt
index 2102248005b5be5568aff5719c529c2374bb6f3f..46c030a49186faabaa588afd2d284975c72c2017 100644 (file)
@@ -582,6 +582,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
        bootmem_debug   [KNL] Enable bootmem allocator debug messages.
 
+       bert_disable    [ACPI]
+                       Disable BERT OS support on buggy BIOSes.
+
        bttv.card=      [HW,V4L] bttv (bt848 + bt878 based grabber cards)
        bttv.radio=     Most important insmod options are available as
                        kernel args too.
@@ -687,6 +690,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        [SPARC64] tick
                        [X86-64] hpet,tsc
 
+       clocksource.arm_arch_timer.evtstrm=
+                       [ARM,ARM64]
+                       Format: <bool>
+                       Enable/disable the eventstream feature of the ARM
+                       architected timer so that code using WFE-based polling
+                       loops can be debugged more effectively on production
+                       systems.
+
        clearcpuid=BITNUM [X86]
                        Disable CPUID feature X for the kernel. See
                        arch/x86/include/asm/cpufeatures.h for the valid bit
@@ -920,9 +931,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
        dhash_entries=  [KNL]
                        Set number of hash buckets for dentry cache.
 
+       disable_1tb_segments [PPC]
+                       Disables the use of 1TB hash page table segments. This
+                       causes the kernel to fall back to 256MB segments which
+                       can be useful when debugging issues that require an SLB
+                       miss to occur.
+
        disable=        [IPV6]
                        See Documentation/networking/ipv6.txt.
 
+       disable_radix   [PPC]
+                       Disable RADIX MMU mode on POWER9
+
        disable_cpu_apicid= [X86,APIC,SMP]
                        Format: <int>
                        The number of initial APIC ID for the
@@ -1185,6 +1205,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        Address Range Mirroring feature even if your box
                        doesn't support it.
 
+       efivar_ssdt=    [EFI; X86] Name of an EFI variable that contains an SSDT
+                       that is to be dynamically loaded by Linux. If there are
+                       multiple variables with the same name but with different
+                       vendor GUIDs, all of them will be loaded. See
+                       Documentation/acpi/ssdt-overlays.txt for details.
+
+
        eisa_irq_edge=  [PARISC,HW]
                        See header of drivers/parisc/eisa.c.
 
@@ -1803,12 +1830,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
        js=             [HW,JOY] Analog joystick
                        See Documentation/input/joystick.txt.
 
-       kaslr/nokaslr   [X86]
-                       Enable/disable kernel and module base offset ASLR
-                       (Address Space Layout Randomization) if built into
-                       the kernel. When CONFIG_HIBERNATION is selected,
-                       kASLR is disabled by default. When kASLR is enabled,
-                       hibernation will be disabled.
+       nokaslr         [KNL]
+                       When CONFIG_RANDOMIZE_BASE is set, this disables
+                       kernel and module base offset ASLR (Address Space
+                       Layout Randomization).
 
        keepinitrd      [HW,ARM]
 
@@ -2295,6 +2320,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        Note that if CONFIG_MODULE_SIG_FORCE is set, that
                        is always true, so this option does nothing.
 
+       module_blacklist=  [KNL] Do not load a comma-separated list of
+                       modules.  Useful for debugging problem modules.
+
        mousedev.tap_time=
                        [MOUSE] Maximum time between finger touching and
                        leaving touchpad surface for touch to be considered
@@ -2788,8 +2816,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        timer: [X86] Force use of architectural NMI
                                timer mode (see also oprofile.timer
                                for generic hr timer mode)
-                               [s390] Force legacy basic mode sampling
-                                (report cpu_type "timer")
 
        oops=panic      Always panic on oopses. Default is to just kill the
                        process, but there is a small probability of
@@ -3159,6 +3185,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        Format: <bool>  (1/Y/y=enable, 0/N/n=disable)
                        default: disabled
 
+       printk.devkmsg={on,off,ratelimit}
+                       Control writing to /dev/kmsg.
+                       on - unlimited logging to /dev/kmsg from userspace
+                       off - logging to /dev/kmsg disabled
+                       ratelimit - ratelimit the logging
+                       Default: ratelimit
+
        printk.time=    Show timing data prefixed to each printk message line
                        Format: <bool>  (1/Y/y=enable, 0/N/n=disable)
 
@@ -3556,7 +3589,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
        relax_domain_level=
                        [KNL, SMP] Set scheduler's default relax_domain_level.
-                       See Documentation/cgroups/cpusets.txt.
+                       See Documentation/cgroup-v1/cpusets.txt.
 
        relative_sleep_states=
                        [SUSPEND] Use sleep state labeling where the deepest
@@ -3603,6 +3636,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                                present during boot.
                nocompress      Don't compress/decompress hibernation images.
                no              Disable hibernation and resume.
+               protect_image   Turn on image protection during restoration
+                               (that will set all pages holding image data
+                               during restoration read-only).
 
        retain_initrd   [RAM] Keep initrd memory after extraction
 
@@ -3841,6 +3877,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        using these two parameters to set the minimum and
                        maximum port values.
 
+       sunrpc.svc_rpc_per_connection_limit=
+                       [NFS,SUNRPC]
+                       Limit the number of requests that the server will
+                       process in parallel from a single connection.
+                       The default value is 0 (no limit).
+
        sunrpc.pool_mode=
                        [NFS]
                        Control how the NFS server code allocates CPUs to
@@ -3876,7 +3918,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
        swapaccount=[0|1]
                        [KNL] Enable accounting of swap in memory resource
                        controller if no parameter or 1 is given or disable
-                       it if 0 is given (See Documentation/cgroups/memory.txt)
+                       it if 0 is given (See Documentation/cgroup-v1/memory.txt)
 
        swiotlb=        [ARM,IA-64,PPC,MIPS,X86]
                        Format: { <int> | force }
@@ -4001,8 +4043,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
        trace_event=[event-list]
                        [FTRACE] Set and start specified trace events in order
-                       to facilitate early boot debugging.
-                       See also Documentation/trace/events.txt
+                       to facilitate early boot debugging. The event-list is a
+                       comma separated list of trace events to enable. See
+                       also Documentation/trace/events.txt
 
        trace_options=[option-list]
                        [FTRACE] Enable or disable tracer options at boot.