]> Pileus Git - ~andy/linux/blobdiff - Documentation/kernel-parameters.txt
Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck...
[~andy/linux] / Documentation / kernel-parameters.txt
index b9589127b3ee803d8be90124855661415fc0f45a..203f4a9d9efe9ae1b2384c6d040cfd3d6f93a603 100644 (file)
@@ -235,10 +235,61 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        Format: To spoof as Windows 98: ="Microsoft Windows"
 
        acpi_osi=       [HW,ACPI] Modify list of supported OS interface strings
-                       acpi_osi="string1"      # add string1 -- only one string
-                       acpi_osi="!string2"     # remove built-in string2
+                       acpi_osi="string1"      # add string1
+                       acpi_osi="!string2"     # remove string2
+                       acpi_osi=!*             # remove all strings
+                       acpi_osi=!              # disable all built-in OS vendor
+                                                 strings
                        acpi_osi=               # disable all strings
 
+                       'acpi_osi=!' can be used in combination with single or
+                       multiple 'acpi_osi="string1"' to support specific OS
+                       vendor string(s).  Note that such command can only
+                       affect the default state of the OS vendor strings, thus
+                       it cannot affect the default state of the feature group
+                       strings and the current state of the OS vendor strings,
+                       specifying it multiple times through kernel command line
+                       is meaningless.  This command is useful when one do not
+                       care about the state of the feature group strings which
+                       should be controlled by the OSPM.
+                       Examples:
+                         1. 'acpi_osi=! acpi_osi="Windows 2000"' is equivalent
+                            to 'acpi_osi="Windows 2000" acpi_osi=!', they all
+                            can make '_OSI("Windows 2000")' TRUE.
+
+                       'acpi_osi=' cannot be used in combination with other
+                       'acpi_osi=' command lines, the _OSI method will not
+                       exist in the ACPI namespace.  NOTE that such command can
+                       only affect the _OSI support state, thus specifying it
+                       multiple times through kernel command line is also
+                       meaningless.
+                       Examples:
+                         1. 'acpi_osi=' can make 'CondRefOf(_OSI, Local1)'
+                            FALSE.
+
+                       'acpi_osi=!*' can be used in combination with single or
+                       multiple 'acpi_osi="string1"' to support specific
+                       string(s).  Note that such command can affect the
+                       current state of both the OS vendor strings and the
+                       feature group strings, thus specifying it multiple times
+                       through kernel command line is meaningful.  But it may
+                       still not able to affect the final state of a string if
+                       there are quirks related to this string.  This command
+                       is useful when one want to control the state of the
+                       feature group strings to debug BIOS issues related to
+                       the OSPM features.
+                       Examples:
+                         1. 'acpi_osi="Module Device" acpi_osi=!*' can make
+                            '_OSI("Module Device")' FALSE.
+                         2. 'acpi_osi=!* acpi_osi="Module Device"' can make
+                            '_OSI("Module Device")' TRUE.
+                         3. 'acpi_osi=! acpi_osi=!* acpi_osi="Windows 2000"' is
+                            equivalent to
+                            'acpi_osi=!* acpi_osi=! acpi_osi="Windows 2000"'
+                            and
+                            'acpi_osi=!* acpi_osi="Windows 2000" acpi_osi=!',
+                            they all will make '_OSI("Windows 2000")' TRUE.
+
        acpi_pm_good    [X86]
                        Override the pmtimer bug detection: force the kernel
                        to assume that this machine's pmtimer latches its value
@@ -429,6 +480,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        Format: <io>,<irq>,<mode>
                        See header of drivers/net/hamradio/baycom_ser_hdx.c.
 
+       blkdevparts=    Manual partition parsing of block device(s) for
+                       embedded devices based on command line input.
+                       See Documentation/block/cmdline-partition.txt
+
        boot_delay=     Milliseconds to delay each printk during boot.
                        Values larger than 10 seconds (10000) are changed to
                        no delay (0).
@@ -1306,7 +1361,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        pages. In the event, a node is too small to have both
                        kernelcore and Movable pages, kernelcore pages will
                        take priority and other nodes will have a larger number
-                       of kernelcore pages.  The Movable zone is used for the
+                       of Movable pages.  The Movable zone is used for the
                        allocation of pages that may be reclaimed or moved
                        by the page migration subsystem.  This means that
                        HugeTLB pages may not be allocated from this zone.
@@ -1847,6 +1902,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        will be sent.
                        The default is to send the implementation identification
                        information.
+       
+       nfs.recover_lost_locks =
+                       [NFSv4] Attempt to recover locks that were lost due
+                       to a lease timeout on the server. Please note that
+                       doing this risks data corruption, since there are
+                       no guarantees that the file will remain unchanged
+                       after the locks are lost.
+                       If you want to enable the kernel legacy behaviour of
+                       attempting to recover these locks, then set this
+                       parameter to '1'.
+                       The default parameter value of '0' causes the kernel
+                       not to attempt recovery of lost locks.
 
        nfsd.nfs4_disable_idmapping=
                        [NFSv4] When set to the default of '1', the NFSv4
@@ -2532,7 +2599,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
        ramdisk_size=   [RAM] Sizes of RAM disks in kilobytes
                        See Documentation/blockdev/ramdisk.txt.
 
-       rcu_nocbs=      [KNL,BOOT]
+       rcu_nocbs=      [KNL]
                        In kernels built with CONFIG_RCU_NOCB_CPU=y, set
                        the specified list of CPUs to be no-callback CPUs.
                        Invocation of these CPUs' RCU callbacks will
@@ -2545,7 +2612,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        real-time workloads.  It can also improve energy
                        efficiency for asymmetric multiprocessors.
 
-       rcu_nocb_poll   [KNL,BOOT]
+       rcu_nocb_poll   [KNL]
                        Rather than requiring that offloaded CPUs
                        (specified by rcu_nocbs= above) explicitly
                        awaken the corresponding "rcuoN" kthreads,
@@ -2556,126 +2623,145 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        energy efficiency by requiring that the kthreads
                        periodically wake up to do the polling.
 
-       rcutree.blimit= [KNL,BOOT]
+       rcutree.blimit= [KNL]
                        Set maximum number of finished RCU callbacks to process
                        in one batch.
 
-       rcutree.fanout_leaf=    [KNL,BOOT]
+       rcutree.rcu_fanout_leaf= [KNL]
                        Increase the number of CPUs assigned to each
                        leaf rcu_node structure.  Useful for very large
                        systems.
 
-       rcutree.jiffies_till_first_fqs= [KNL,BOOT]
+       rcutree.jiffies_till_first_fqs= [KNL]
                        Set delay from grace-period initialization to
                        first attempt to force quiescent states.
                        Units are jiffies, minimum value is zero,
                        and maximum value is HZ.
 
-       rcutree.jiffies_till_next_fqs= [KNL,BOOT]
+       rcutree.jiffies_till_next_fqs= [KNL]
                        Set delay between subsequent attempts to force
                        quiescent states.  Units are jiffies, minimum
                        value is one, and maximum value is HZ.
 
-       rcutree.qhimark=        [KNL,BOOT]
+       rcutree.qhimark= [KNL]
                        Set threshold of queued
                        RCU callbacks over which batch limiting is disabled.
 
-       rcutree.qlowmark=       [KNL,BOOT]
+       rcutree.qlowmark= [KNL]
                        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.
-
-       rcutree.rcu_idle_gp_delay=      [KNL,BOOT]
+       rcutree.rcu_idle_gp_delay= [KNL]
                        Set wakeup interval for idle CPUs that have
                        RCU callbacks (RCU_FAST_NO_HZ=y).
 
-       rcutree.rcu_idle_lazy_gp_delay= [KNL,BOOT]
+       rcutree.rcu_idle_lazy_gp_delay= [KNL]
                        Set wakeup interval for idle CPUs that have
                        only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y).
                        Lazy RCU callbacks are those which RCU can
                        prove do nothing more than free memory.
 
-       rcutorture.fqs_duration= [KNL,BOOT]
+       rcutorture.fqs_duration= [KNL]
                        Set duration of force_quiescent_state bursts.
 
-       rcutorture.fqs_holdoff= [KNL,BOOT]
+       rcutorture.fqs_holdoff= [KNL]
                        Set holdoff time within force_quiescent_state bursts.
 
-       rcutorture.fqs_stutter= [KNL,BOOT]
+       rcutorture.fqs_stutter= [KNL]
                        Set wait time between force_quiescent_state bursts.
 
-       rcutorture.irqreader= [KNL,BOOT]
-                       Test RCU readers from irq handlers.
+       rcutorture.gp_exp= [KNL]
+                       Use expedited update-side primitives.
+
+       rcutorture.gp_normal= [KNL]
+                       Use normal (non-expedited) update-side primitives.
+                       If both gp_exp and gp_normal are set, do both.
+                       If neither gp_exp nor gp_normal are set, still
+                       do both.
 
-       rcutorture.n_barrier_cbs= [KNL,BOOT]
+       rcutorture.n_barrier_cbs= [KNL]
                        Set callbacks/threads for rcu_barrier() testing.
 
-       rcutorture.nfakewriters= [KNL,BOOT]
+       rcutorture.nfakewriters= [KNL]
                        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]
+       rcutorture.nreaders= [KNL]
                        Set number of RCU readers.
 
-       rcutorture.onoff_holdoff= [KNL,BOOT]
+       rcutorture.object_debug= [KNL]
+                       Enable debug-object double-call_rcu() testing.
+
+       rcutorture.onoff_holdoff= [KNL]
                        Set time (s) after boot for CPU-hotplug testing.
 
-       rcutorture.onoff_interval= [KNL,BOOT]
+       rcutorture.onoff_interval= [KNL]
                        Set time (s) between CPU-hotplug operations, or
                        zero to disable CPU-hotplug testing.
 
-       rcutorture.shuffle_interval= [KNL,BOOT]
+       rcutorture.rcutorture_runnable= [BOOT]
+                       Start rcutorture running at boot time.
+
+       rcutorture.shuffle_interval= [KNL]
                        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]
+       rcutorture.shutdown_secs= [KNL]
                        Set time (s) after boot system shutdown.  This
                        is useful for hands-off automated testing.
 
-       rcutorture.stall_cpu= [KNL,BOOT]
+       rcutorture.stall_cpu= [KNL]
                        Duration of CPU stall (s) to test RCU CPU stall
                        warnings, zero to disable.
 
-       rcutorture.stall_cpu_holdoff= [KNL,BOOT]
+       rcutorture.stall_cpu_holdoff= [KNL]
                        Time to wait (s) after boot before inducing stall.
 
-       rcutorture.stat_interval= [KNL,BOOT]
+       rcutorture.stat_interval= [KNL]
                        Time (s) between statistics printk()s.
 
-       rcutorture.stutter= [KNL,BOOT]
+       rcutorture.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 RCU's
                        ability to transition abruptly to and from idle.
 
-       rcutorture.test_boost= [KNL,BOOT]
+       rcutorture.test_boost= [KNL]
                        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]
+       rcutorture.test_boost_duration= [KNL]
                        Duration (s) of each individual boost test.
 
-       rcutorture.test_boost_interval= [KNL,BOOT]
+       rcutorture.test_boost_interval= [KNL]
                        Interval (s) between each boost test.
 
-       rcutorture.test_no_idle_hz= [KNL,BOOT]
+       rcutorture.test_no_idle_hz= [KNL]
                        Test RCU's dyntick-idle handling.  See also the
                        rcutorture.shuffle_interval parameter.
 
-       rcutorture.torture_type= [KNL,BOOT]
+       rcutorture.torture_type= [KNL]
                        Specify the RCU implementation to test.
 
-       rcutorture.verbose= [KNL,BOOT]
+       rcutorture.verbose= [KNL]
                        Enable additional printk() statements.
 
+       rcupdate.rcu_expedited= [KNL]
+                       Use expedited grace-period primitives, for
+                       example, synchronize_rcu_expedited() instead
+                       of synchronize_rcu().  This reduces latency,
+                       but can increase CPU utilization, degrade
+                       real-time latency, and degrade energy efficiency.
+
+       rcupdate.rcu_cpu_stall_suppress= [KNL]
+                       Suppress RCU CPU stall warning messages.
+
+       rcupdate.rcu_cpu_stall_timeout= [KNL]
+                       Set timeout for RCU CPU stall warning messages.
+
        rdinit=         [KNL]
                        Format: <full_path>
                        Run specified binary instead of /init from the ramdisk,
@@ -3322,6 +3408,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                                    them quite hard to use for exploits but
                                    might break your system.
 
+       vt.color=       [VT] Default text color.
+                       Format: 0xYX, X = foreground, Y = background.
+                       Default: 0x07 = light gray on black.
+
        vt.cur_default= [VT] Default cursor shape.
                        Format: 0xCCBBAA, where AA, BB, and CC are the same as
                        the parameters of the <Esc>[?A;B;Cc escape sequence;
@@ -3361,6 +3451,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        overridden by individual drivers. 0 will hide
                        cursors, 1 will display them.
 
+       vt.italic=      [VT] Default color for italic text; 0-15.
+                       Default: 2 = green.
+
+       vt.underline=   [VT] Default color for underlined text; 0-15.
+                       Default: 3 = cyan.
+
        watchdog timers [HW,WDT] For information on watchdog timers,
                        see Documentation/watchdog/watchdog-parameters.txt
                        or other driver-specific files in the