Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

Docs: admin/kernel-parameters: edit a few boot options

Clean up some of admin-guide/kernel-parameters.txt:

a. "smt" should be "smt=" (S390)
b. (dropped)
c. Sparc supports the vdso= boot option
d. make the tp_printk options (2) formatting similar to other options
by adding spacing
e. add "trace_clock=" with a reference to Documentation/trace/ftrace.rst
f. use [IA-64] as documented instead of [ia64]
g. fix formatting and text for test_suspend=
h. fix formatting for swapaccount=
i. fix formatting and grammar for video.brightness_switch_enabled=

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-ia64@vger.kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-pm@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

authored by

Randy Dunlap and committed by
Jonathan Corbet
59bdbbd5 82850028

+36 -11
+36 -11
Documentation/admin-guide/kernel-parameters.txt
··· 2814 2814 different yeeloong laptops. 2815 2815 Example: machtype=lemote-yeeloong-2f-7inch 2816 2816 2817 - max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater 2817 + max_addr=nn[KMG] [KNL,BOOT,IA-64] All physical memory greater 2818 2818 than or equal to this physical address is ignored. 2819 2819 2820 2820 maxcpus= [SMP] Maximum number of processors that an SMP kernel ··· 3057 3057 3058 3058 mga= [HW,DRM] 3059 3059 3060 - min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this 3060 + min_addr=nn[KMG] [KNL,BOOT,IA-64] All physical memory below this 3061 3061 physical address is ignored. 3062 3062 3063 3063 mini2440= [ARM,HW,KNL] ··· 5388 5388 1: Fast pin select (default) 5389 5389 2: ATC IRMode 5390 5390 5391 - smt [KNL,S390] Set the maximum number of threads (logical 5391 + smt= [KNL,S390] Set the maximum number of threads (logical 5392 5392 CPUs) to use per physical CPU on systems capable of 5393 5393 symmetric multithreading (SMT). Will be capped to the 5394 5394 actual hardware limit. ··· 5743 5743 This parameter controls use of the Protected 5744 5744 Execution Facility on pSeries. 5745 5745 5746 - swapaccount=[0|1] 5747 - [KNL] Enable accounting of swap in memory resource 5746 + swapaccount= [KNL] 5747 + Format: [0|1] 5748 + Enable accounting of swap in memory resource 5748 5749 controller if no parameter or 1 is given or disable 5749 5750 it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst) 5750 5751 ··· 5791 5790 5792 5791 tdfx= [HW,DRM] 5793 5792 5794 - test_suspend= [SUSPEND][,N] 5793 + test_suspend= [SUSPEND] 5794 + Format: { "mem" | "standby" | "freeze" }[,N] 5795 5795 Specify "mem" (for Suspend-to-RAM) or "standby" (for 5796 5796 standby suspend) or "freeze" (for suspend type freeze) 5797 5797 as the system sleep state during system startup with ··· 5879 5877 trace_buf_size=nn[KMG] 5880 5878 [FTRACE] will set tracing buffer size on each cpu. 5881 5879 5880 + trace_clock= [FTRACE] Set the clock used for tracing events 5881 + at boot up. 5882 + local - Use the per CPU time stamp counter 5883 + (converted into nanoseconds). Fast, but 5884 + depending on the architecture, may not be 5885 + in sync between CPUs. 5886 + global - Event time stamps are synchronize across 5887 + CPUs. May be slower than the local clock, 5888 + but better for some race conditions. 5889 + counter - Simple counting of events (1, 2, ..) 5890 + note, some counts may be skipped due to the 5891 + infrastructure grabbing the clock more than 5892 + once per event. 5893 + uptime - Use jiffies as the time stamp. 5894 + perf - Use the same clock that perf uses. 5895 + mono - Use ktime_get_mono_fast_ns() for time stamps. 5896 + mono_raw - Use ktime_get_raw_fast_ns() for time 5897 + stamps. 5898 + boot - Use ktime_get_boot_fast_ns() for time stamps. 5899 + Architectures may add more clocks. See 5900 + Documentation/trace/ftrace.rst for more details. 5901 + 5882 5902 trace_event=[event-list] 5883 5903 [FTRACE] Set and start specified trace events in order 5884 5904 to facilitate early boot debugging. The event-list is a ··· 5923 5899 See also Documentation/trace/ftrace.rst "trace options" 5924 5900 section. 5925 5901 5926 - tp_printk[FTRACE] 5902 + tp_printk [FTRACE] 5927 5903 Have the tracepoints sent to printk as well as the 5928 5904 tracing ring buffer. This is useful for early boot up 5929 5905 where the system hangs or reboots and does not give the ··· 5945 5921 frequency tracepoints such as irq or sched, can cause 5946 5922 the system to live lock. 5947 5923 5948 - tp_printk_stop_on_boot[FTRACE] 5924 + tp_printk_stop_on_boot [FTRACE] 5949 5925 When tp_printk (above) is set, it can cause a lot of noise 5950 5926 on the console. It may be useful to only include the 5951 5927 printing of events during boot up, as user space may ··· 6294 6270 HIGHMEM regardless of setting 6295 6271 of CONFIG_HIGHPTE. 6296 6272 6297 - vdso= [X86,SH] 6273 + vdso= [X86,SH,SPARC] 6298 6274 On X86_32, this is an alias for vdso32=. Otherwise: 6299 6275 6300 6276 vdso=1: enable VDSO (the default) ··· 6320 6296 video= [FB] Frame buffer configuration 6321 6297 See Documentation/fb/modedb.rst. 6322 6298 6323 - video.brightness_switch_enabled= [0,1] 6299 + video.brightness_switch_enabled= [ACPI] 6300 + Format: [0|1] 6324 6301 If set to 1, on receiving an ACPI notify event 6325 6302 generated by hotkey, video driver will adjust brightness 6326 6303 level and then send out the event to user space through 6327 - the allocated input device; If set to 0, video driver 6304 + the allocated input device. If set to 0, video driver 6328 6305 will only send out the event without touching backlight 6329 6306 brightness level. 6330 6307 default: 1