Re: [PATCH 1/3 v3] Docs: admin/kernel-parameters: edit a few boot options

[Rafael J. Wysocki]

On Sun, Apr 3, 2022 at 7:48 AM Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxxxxx>
> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
> Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
> Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
> Cc: linux-s390@xxxxxxxxxxxxxxx
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: sparclinux@xxxxxxxxxxxxxxx
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: linux-ia64@xxxxxxxxxxxxxxx
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: Len Brown <lenb@xxxxxxxxxx>
> Cc: linux-pm@xxxxxxxxxxxxxxx
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Jonathan Corbet <corbet@xxxxxxx>
> Cc: linux-doc@xxxxxxxxxxxxxxx

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

for the test_suspend and ACPI video pieces.

> ---
> v3: add trace_clock= specifics (Steven)
> v2: drop "smt-enabled" for arch/powerpc/ (Michael)
>
>  Documentation/admin-guide/kernel-parameters.txt |   47 ++++++++++----
>  1 file changed, 36 insertions(+), 11 deletions(-)
>
> --- linux-next-20220331.orig/Documentation/admin-guide/kernel-parameters.txt
> +++ linux-next-20220331/Documentation/admin-guide/kernel-parameters.txt
> @@ -2814,7 +2814,7 @@
>                         different yeeloong laptops.
>                         Example: machtype=lemote-yeeloong-2f-7inch
>
> -       max_addr=nn[KMG]        [KNL,BOOT,ia64] All physical memory greater
> +       max_addr=nn[KMG]        [KNL,BOOT,IA-64] All physical memory greater
>                         than or equal to this physical address is ignored.
>
>         maxcpus=        [SMP] Maximum number of processors that an SMP kernel
> @@ -3057,7 +3057,7 @@
>
>         mga=            [HW,DRM]
>
> -       min_addr=nn[KMG]        [KNL,BOOT,ia64] All physical memory below this
> +       min_addr=nn[KMG]        [KNL,BOOT,IA-64] All physical memory below this
>                         physical address is ignored.
>
>         mini2440=       [ARM,HW,KNL]
> @@ -5388,7 +5388,7 @@
>                                 1: Fast pin select (default)
>                                 2: ATC IRMode
>
> -       smt             [KNL,S390] Set the maximum number of threads (logical
> +       smt=            [KNL,S390] Set the maximum number of threads (logical
>                         CPUs) to use per physical CPU on systems capable of
>                         symmetric multithreading (SMT). Will be capped to the
>                         actual hardware limit.
> @@ -5774,8 +5774,9 @@
>                         This parameter controls use of the Protected
>                         Execution Facility on pSeries.
>
> -       swapaccount=[0|1]
> -                       [KNL] Enable accounting of swap in memory resource
> +       swapaccount=    [KNL]
> +                       Format: [0|1]
> +                       Enable accounting of swap in memory resource
>                         controller if no parameter or 1 is given or disable
>                         it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst)
>
> @@ -5821,7 +5822,8 @@
>
>         tdfx=           [HW,DRM]
>
> -       test_suspend=   [SUSPEND][,N]
> +       test_suspend=   [SUSPEND]
> +                       Format: { "mem" | "standby" | "freeze" }[,N]
>                         Specify "mem" (for Suspend-to-RAM) or "standby" (for
>                         standby suspend) or "freeze" (for suspend type freeze)
>                         as the system sleep state during system startup with
> @@ -5908,6 +5910,28 @@
>         trace_buf_size=nn[KMG]
>                         [FTRACE] will set tracing buffer size on each cpu.
>
> +       trace_clock=    [FTRACE] Set the clock used for tracing events
> +                       at boot up.
> +                       local - Use the per CPU time stamp counter
> +                               (converted into nanoseconds). Fast, but
> +                               depending on the architecture, may not be
> +                               in sync between CPUs.
> +                       global - Event time stamps are synchronize across
> +                               CPUs. May be slower than the local clock,
> +                               but better for some race conditions.
> +                       counter - Simple counting of events (1, 2, ..)
> +                               note, some counts may be skipped due to the
> +                               infrastructure grabbing the clock more than
> +                               once per event.
> +                       uptime - Use jiffies as the time stamp.
> +                       perf - Use the same clock that perf uses.
> +                       mono - Use ktime_get_mono_fast_ns() for time stamps.
> +                       mono_raw - Use ktime_get_raw_fast_ns() for time
> +                               stamps.
> +                       boot - Use ktime_get_boot_fast_ns() for time stamps.
> +                       Architectures may add more clocks. See
> +                       Documentation/trace/ftrace.rst for more details.
> +
>         trace_event=[event-list]
>                         [FTRACE] Set and start specified trace events in order
>                         to facilitate early boot debugging. The event-list is a
> @@ -5930,7 +5954,7 @@
>                         See also Documentation/trace/ftrace.rst "trace options"
>                         section.
>
> -       tp_printk[FTRACE]
> +       tp_printk       [FTRACE]
>                         Have the tracepoints sent to printk as well as the
>                         tracing ring buffer. This is useful for early boot up
>                         where the system hangs or reboots and does not give the
> @@ -5952,7 +5976,7 @@
>                         frequency tracepoints such as irq or sched, can cause
>                         the system to live lock.
>
> -       tp_printk_stop_on_boot[FTRACE]
> +       tp_printk_stop_on_boot [FTRACE]
>                         When tp_printk (above) is set, it can cause a lot of noise
>                         on the console. It may be useful to only include the
>                         printing of events during boot up, as user space may
> @@ -6301,7 +6325,7 @@
>                                         HIGHMEM regardless of setting
>                                         of CONFIG_HIGHPTE.
>
> -       vdso=           [X86,SH]
> +       vdso=           [X86,SH,SPARC]
>                         On X86_32, this is an alias for vdso32=.  Otherwise:
>
>                         vdso=1: enable VDSO (the default)
> @@ -6327,11 +6351,12 @@
>         video=          [FB] Frame buffer configuration
>                         See Documentation/fb/modedb.rst.
>
> -       video.brightness_switch_enabled= [0,1]
> +       video.brightness_switch_enabled= [ACPI]
> +                       Format: [0|1]
>                         If set to 1, on receiving an ACPI notify event
>                         generated by hotkey, video driver will adjust brightness
>                         level and then send out the event to user space through
> -                       the allocated input device; If set to 0, video driver
> +                       the allocated input device. If set to 0, video driver
>                         will only send out the event without touching backlight
>                         brightness level.
>                         default: 1