Commit Graph

53 Commits

Author SHA1 Message Date
Anna-Maria Behnsen
bd7c8ff9fe treewide: Fix wrong singular form of jiffies in comments
There are several comments all over the place, which uses a wrong singular
form of jiffies.

Replace 'jiffie' by 'jiffy'. No functional change.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Link: https://lore.kernel.org/all/20240904-devel-anna-maria-b4-timers-flseep-v1-3-e98760256370@linutronix.de
2024-09-08 20:47:40 +02:00
Oleg Nesterov
5097cbcb38 sched/isolation: Prevent boot crash when the boot CPU is nohz_full
Documentation/timers/no_hz.rst states that the "nohz_full=" mask must not
include the boot CPU, which is no longer true after:

  08ae95f4fd ("nohz_full: Allow the boot CPU to be nohz_full").

However after:

  aae17ebb53 ("workqueue: Avoid using isolated cpus' timers on queue_delayed_work")

the kernel will crash at boot time in this case; housekeeping_any_cpu()
returns an invalid CPU number until smp_init() brings the first
housekeeping CPU up.

Change housekeeping_any_cpu() to check the result of cpumask_any_and() and
return smp_processor_id() in this case.

This is just the simple and backportable workaround which fixes the
symptom, but smp_processor_id() at boot time should be safe at least for
type == HK_TYPE_TIMER, this more or less matches the tick_do_timer_boot_cpu
logic.

There is no worry about cpu_down(); tick_nohz_cpu_down() will not allow to
offline tick_do_timer_cpu (the 1st online housekeeping CPU).

Fixes: aae17ebb53 ("workqueue: Avoid using isolated cpus' timers on queue_delayed_work")
Reported-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240411143905.GA19288@redhat.com
Closes: https://lore.kernel.org/all/20240402105847.GA24832@redhat.com/
2024-04-28 10:07:12 +02:00
Randy Dunlap
96e3cc270d Documentation: use capitalization for chapters and acronyms
Use capital letters in acronyms for CD-ROM, FPGA, and PCMCIA.

Use capital letter in the first word of chapter headings for
Locking, Timers, and "Brief tutorial on CRC computation".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Moritz Fischer <mdf@kernel.org>
Cc: Wu Hao <hao.wu@intel.com>
Cc: Tom Rix <trix@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Reviewed-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20230516001518.14514-1-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-05-16 12:49:31 -06:00
Geert Uytterhoeven
4c093cbb89 Documentation: timers: hrtimers: Make hybrid union historical
Non-scalar time was removed from the ktime hybrid union in v3.17, and
the union itself followed suit in v4.10.

Make it clear that ktime_t is always a 64bit scalar type, to avoid
confusing the casual reader.

While at it, fix a spelling mistake.

Fixes: 24e4a8c3e8 ("ktime: Kill non-scalar ktime_t implementation for 2038")
Fixes: 2456e85535 ("ktime: Get rid of the union")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/59250a3d1c2c827b5c1833169a6e652ca6a784e6.1683021785.git.geert+renesas@glider.be
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-05-02 10:49:58 -06:00
Thomas Gleixner
87bdd932e8 Documentation: Replace del_timer/del_timer_sync()
Adjust to the new preferred function names.

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Link: https://lore.kernel.org/r/20221123201625.075320635@linutronix.de
2022-11-24 15:09:11 +01:00
Paul E. McKenney
e2c73a6860 rcu: Remove the RCU_FAST_NO_HZ Kconfig option
All of the uses of CONFIG_RCU_FAST_NO_HZ=y that I have seen involve
systems with RCU callbacks offloaded.  In this situation, all that this
Kconfig option does is slow down idle entry/exit with an additional
allways-taken early exit.  If this is the only use case, then this
Kconfig option nothing but an attractive nuisance that needs to go away.

This commit therefore removes the RCU_FAST_NO_HZ Kconfig option.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-11-30 17:24:47 -08:00
Borislav Petkov
15ce51f55e Documentation/no_hz: Introduce "dyntick-idle mode" before using it
The CONFIG_NO_HZ_IDLE paragraph is using "dyntick-idle mode" before
having defined it while the definition comes a couple of paragraphs
later.

That is leaving the reader with scratching head what that dyntick-idle
mode might be. Pull its definition up so that it is clear.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20210914203355.21360-1-bp@alien8.de
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-09-27 11:31:11 -06:00
Randy Dunlap
9e255e2b9a Documentation: drop optional BOMs
A few of the Documentation .rst files begin with a Unicode
byte order mark (BOM). The BOM may signify endianess for
16-bit or 32-bit encodings or indicate that the text stream
is indeed Unicode. We don't need it for either of those uses.
It may also interfere with (confuse) some software.

Since we don't need it and its use is optional, just delete
the uses of it in Documentation/.

https://en.wikipedia.org/wiki/Byte_order_mark

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Link: https://lore.kernel.org/r/20210506231907.14359-1-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-05-10 15:17:34 -06:00
Joe Perches
05a5f51ca5 Documentation: Replace lkml.org links with lore
Replace the lkml.org links with lore to better use a single source
that's more likely to stay available long-term.

Done by bash script:

cvt_lkml_to_lore ()
{
    tmpfile=$(mktemp ./.cvt_links.XXXXXXX)

    header=$(echo $1 | sed 's@/lkml/@/lkml/headers/@')

    wget -qO - $header > $tmpfile
    if [[ $? == 0 ]] ; then
	link=$(grep -i '^Message-Id:' $tmpfile | head -1 | \
		   sed -r -e 's/^\s*Message-Id:\s*<\s*//' -e  's/\s*>\s*$//' -e 's@^@https://lore.kernel.org/r/@')
	#    echo "testlink: $link"
	if [ -n "$link" ] ; then
	    wget -qO - $link > /dev/null
	    if [[ $? == 0 ]] ; then
		echo $link
	    fi
	fi
    fi

    rm -f $tmpfile
}

git grep -P -o "\bhttps?://(?:www.)?lkml.org/lkml[\/\w]+" $@ |
    while read line ; do
	echo $line
	file=$(echo $line | cut -f1 -d':')
	link=$(echo $line | cut -f2- -d':')
	newlink=$(cvt_lkml_to_lore $link)
	if [[ -n "$newlink" ]] ; then
	    sed -i -e "s#\b$link\b#$newlink#" $file
	fi
    done

Link: https://lore.kernel.org/patchwork/patch/1265849/#1462688
Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/77cdb7f32cfb087955bfc3600b86c40bed5d4104.camel@perches.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-01-11 12:47:38 -07:00
Julia Lawall
61ebd0d0ae docs: timers: drop documentation about LB_BIAS
The LB_BIAS feature was removed in commit 1c1b8a7b03 ("sched/fair:
Replace source_load() & target_load() with weighted_cpuload()"), so drop
the mention that it is disabled in the no_hz case.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

Link: https://lore.kernel.org/r/1595088518-28116-1-git-send-email-Julia.Lawall@inria.fr
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-23 14:32:44 -06:00
Heiner Kallweit
c6af13d334 timer: add fsleep for flexible sleeping
Sleeping for a certain amount of time requires use of different
functions, depending on the time period.
Documentation/timers/timers-howto.rst explains when to use which
function, and also checkpatch checks for some potentially
problematic cases.

So let's create a helper that automatically chooses the appropriate
sleep function -> fsleep(), for flexible sleeping

If the delay is a constant, then the compiler should be able to ensure
that the new helper doesn't create overhead. If the delay is not
constant, then the new helper can save some code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06 17:03:34 -07:00
Mauro Carvalho Chehab
113094f743 docs: add some directories to the main documentation index
The contents of those directories were orphaned at the documentation
body.

While those directories could likely be moved to be inside some guide,
I'm opting to just adding their indexes to the main one, removing the
:orphan: and adding the SPDX header.

For the drivers, the rationale is that the documentation contains
a mix of Kernelspace, uAPI and admin-guide. So, better to keep them on
separate directories, as we've be doing with similar subsystem-specific
docs that were not split yet.

For the others, well... I'm too lazy to do the move. Also, it
seems to make sense to keep at least some of those at the main
dir (like kbuild, for example). In any case, a latter patch
could do the move.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2019-07-15 11:03:03 -03:00
Mauro Carvalho Chehab
458f69ef36 docs: timers: convert docs to ReST and rename to *.rst
The conversion here is really trivial: just a bunch of title
markups and very few puntual changes is enough to make it to
be parsed by Sphinx and generate a nice html.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:31:48 -06:00
George Sofianos
3203561d6d Docs: Correct /proc/stat path
The documentation for dynamic ticks in high resolution timers uses an
incorrect path for /proc/stat - fix it.

Signed-off-by: George Sofianos <gsf.greece@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-02-22 08:50:17 -07:00
Henrik Austad
a7ddcea58a Drop all 00-INDEX files from Documentation/
This is a respin with a wider audience (all that get_maintainer returned)
and I know this spams a *lot* of people. Not sure what would be the correct
way, so my apologies for ruining your inbox.

The 00-INDEX files are supposed to give a summary of all files present
in a directory, but these files are horribly out of date and their
usefulness is brought into question. Often a simple "ls" would reveal
the same information as the filenames are generally quite descriptive as
a short introduction to what the file covers (it should not surprise
anyone what Documentation/sched/sched-design-CFS.txt covers)

A few years back it was mentioned that these files were no longer really
needed, and they have since then grown further out of date, so perhaps
it is time to just throw them out.

A short status yields the following _outdated_ 00-INDEX files, first
counter is files listed in 00-INDEX but missing in the directory, last
is files present but not listed in 00-INDEX.

List of outdated 00-INDEX:
Documentation: (4/10)
Documentation/sysctl: (0/1)
Documentation/timers: (1/0)
Documentation/blockdev: (3/1)
Documentation/w1/slaves: (0/1)
Documentation/locking: (0/1)
Documentation/devicetree: (0/5)
Documentation/power: (1/1)
Documentation/powerpc: (0/5)
Documentation/arm: (1/0)
Documentation/x86: (0/9)
Documentation/x86/x86_64: (1/1)
Documentation/scsi: (4/4)
Documentation/filesystems: (2/9)
Documentation/filesystems/nfs: (0/2)
Documentation/cgroup-v1: (0/2)
Documentation/kbuild: (0/4)
Documentation/spi: (1/0)
Documentation/virtual/kvm: (1/0)
Documentation/scheduler: (0/2)
Documentation/fb: (0/1)
Documentation/block: (0/1)
Documentation/networking: (6/37)
Documentation/vm: (1/3)

Then there are 364 subdirectories in Documentation/ with several files that
are missing 00-INDEX alltogether (and another 120 with a single file and no
00-INDEX).

I don't really have an opinion to whether or not we /should/ have 00-INDEX,
but the above 00-INDEX should either be removed or be kept up to date. If
we should keep the files, I can try to keep them updated, but I rather not
if we just want to delete them anyway.

As a starting point, remove all index-files and references to 00-INDEX and
see where the discussion is going.

Signed-off-by: Henrik Austad <henrik@austad.us>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Just-do-it-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: [Almost everybody else]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-09-09 15:08:58 -06:00
Siddaraju DH
9e7c758ec4 timekeeping.txt: Correct maxCount of n-bit binary counter
A n-bit binary counter can count a maximum of 2^n events and the count
value ranges from 0 to (2^n)-1

Signed-off-by: Siddaraju DH <siddarajudh@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-23 09:33:06 -06:00
Paul E. McKenney
a7c8655b07 sched/isolation: Eliminate NO_HZ_FULL_ALL
Commit 6f1982fedd ("sched/isolation: Handle the nohz_full= parameter")
broke CONFIG_NO_HZ_FULL_ALL=y kernels.  This breakage is due to the code
under CONFIG_NO_HZ_FULL_ALL failing to invoke the shiny new housekeeping
functions.  This means that rcutorture scenario TREE04 now emits RCU CPU
stall warnings due to the RCU grace-period kthreads not being awakened
at a time of their choosing, or perhaps even not at all:

[   27.731422] rcu_bh kthread starved for 21001 jiffies! g18446744073709551369 c18446744073709551368 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=3
[   27.731423] rcu_bh          I14936     9      2 0x80080000
[   27.731435] Call Trace:
[   27.731440]  __schedule+0x31a/0x6d0
[   27.731442]  schedule+0x31/0x80
[   27.731446]  schedule_timeout+0x15a/0x320
[   27.731453]  ? call_timer_fn+0x130/0x130
[   27.731457]  rcu_gp_kthread+0x66c/0xea0
[   27.731458]  ? rcu_gp_kthread+0x66c/0xea0

Because no one has complained about CONFIG_NO_HZ_FULL_ALL=y being broken,
I hypothesize that no one is in fact using it, other than rcutorture.
This commit therefore eliminates CONFIG_NO_HZ_FULL_ALL and updates
rcutorture's config files to instead use the nohz_full= kernel parameter
to put the desired CPUs into nohz_full mode.

Fixes: 6f1982fedd ("sched/isolation: Handle the nohz_full= parameter")

Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
2018-02-15 15:40:37 -08:00
stephen lu
44e9f09936 docs: highres: fix broken urls
Some urls is invalid. I find alternative urls.

Signed-off-by: stephen lu <lumotuwe@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-09-26 14:58:23 -06:00
Paul E. McKenney
44c65ff2e3 rcu: Eliminate NOCBs CPU-state Kconfig options
The CONFIG_RCU_NOCB_CPU_ALL, CONFIG_RCU_NOCB_CPU_NONE, and
CONFIG_RCU_NOCB_CPU_ZERO Kconfig options are used only in testing and
are redundant with the rcu_nocbs= boot parameter.  This commit therefore
removes these three Kconfig options and adjusts the rcutorture scripts
to use the boot parameter instead.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08 18:52:43 -07:00
Kees Cook
dfb4357da6 time: Remove CONFIG_TIMER_STATS
Currently CONFIG_TIMER_STATS exposes process information across namespaces:

kernel/time/timer_list.c print_timer():

        SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);

/proc/timer_list:

 #11: <0000000000000000>, hrtimer_wakeup, S:01, do_nanosleep, cron/2570

Given that the tracer can give the same information, this patch entirely
removes CONFIG_TIMER_STATS.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: linux-doc@vger.kernel.org
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Xing Gao <xgao01@email.wm.edu>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jessica Frazelle <me@jessfraz.com>
Cc: kernel-hardening@lists.openwall.com
Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-api@vger.kernel.org
Cc: Arjan van de Ven <arjan@linux.intel.com>
Link: http://lkml.kernel.org/r/20170208192659.GA32582@beast
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-10 11:15:08 +01:00
Shuah Khan
f59c668c0b Doc: update 00-INDEX files to reflect the runnable code move
Update 00-INDEX files with the current file list to reflect the runnable
code move.

Acked-by: Michal Marek <mmarek@suse.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2016-10-10 07:12:09 -06:00
Shuah Khan
155fe001c6 samples: move timers example code from Documentation
Move timers examples to samples and remove it from Documentation
Makefile. Create a new Makefile to build timers. It can be built
from top level directory or from timers directory:

Run make -C samples/timers or cd samples/timers; make

Acked-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2016-09-23 11:51:58 -06:00
Kees Cook
08559657b2 Documentation: fix common spelling mistakes
This fixes several spelling mistakes in the Documentation/ tree, which
are caught by checkpatch.pl's spell checking.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-04-28 07:51:59 -06:00
Cao jin
ac86db349e hrtimers: doc cleanup
It has:
a tense correction(led->leads);
a typo(unevitably->inevitably);

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-04-28 07:13:10 -06:00
Linus Torvalds
37aa7319cd Another relatively boring cycle for the docs tree: typo fixes, translation
updates, etc.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJW6IqKAAoJEI3ONVYwIuV6zawP/2NG5Rh9a/6B9YbtVsXZrWD+
 wCK80j+tbH9yAba54GjdJ2nvMKSYpC62ti4sPwtdSllvd0/e2ZnS4ZLa9sSoMDsH
 GK10mYhUcosDfeNCadT66Wl9o8ICu2QqNvGUtjI1331dcjAKBxLjJfaVQ9nddcdP
 Ksr8+ATr1rQE8YfxdprOnaX06C0FKqaQfRWdBl4FNDh6pb6eeXWnP56A+m3zi7e8
 R2uJGlHwxq3qS27JkQDwiWFb7FVPt1H6bfM9DcgiGfItfgoosW1cExxND4MoqEZT
 8ATE1H4Zbn6QOkq88Wo4vDn3gDIsgy7D7rS69juFNzCajxIOaN8NfPusGFmTCpQU
 cuh6XDYKS2n05RU0tuLB9NxTd+1b50COVHD//dEhjvpF+Z7Ku6yM2LrhTYYvoAsm
 XFYUUrJ8i09D0hllRA8WGE+AYGLvyFV9AE1mJQPepx+9TjBluKuqIoig03kEWfof
 3xXhigFy+WttLQZiqten3YMVSo4xQRNq7FgqZ20dPMF1Exnj1wkwDFrE3SBB3Xcv
 3eN953O12JzL7ja+9/OPMKZt8xs/tzLAScMP4R/nXGG050aecRH/xFFrOlzPDdyQ
 oshon67cMGi5qJdHaOkALqwz89euXv/AMHxGixu1M0zJG81WQm1u6vi9lY7b8Y3q
 ojA8vgsG3AprS9nmxqVh
 =wBKa
 -----END PGP SIGNATURE-----

Merge tag 'docs-for-linus' of git://git.lwn.net/linux

Pul documentation update from Jon Corbet:
 "Another relatively boring cycle for the docs tree: typo fixes,
  translation updates, etc"

* tag 'docs-for-linus' of git://git.lwn.net/linux:
  modsign: Fix documentation on module signing enforcement parameter.
  Doc: nfs: Fix typos in Documentation/filesystems/nfs
  Documentation: kselftest: Remove duplicate word
  doc: fix grammar
  Documentation: Howto: Fixed subtitles style
  Doc: ARM: Fix a typo in clksrc-change-registers.awk
  Documentation/ko_KR: update maintainer information
  Documentation: Fix int/unsigned int comparison
  Documentation: Chinese translation of arm64/silicon-errata.txt
  Documentation:Update Documentation/zh_CN/arm64/booting.txt
  Documentation: HOWTO: remove obsolete info about regression postings
  Doc: ja_JP: Fix a typo in HOWTO
  Doc: i2c: Fix typo in Documentation/i2c
  Doc: DocBook: Fix a typo in device-drivers.tmpl
  Remove "arch" usage in Documentation/features/list-arch.sh
  README: cosmetic fixes
  Documentation/CodingStyle: add space before parenthesis in example macro
  SubmittingPatches: fix spelling of "git send-email"
2016-03-17 12:09:35 -07:00
Mahesh Khanwalkar
f0cd147e61 Documentation: Fix int/unsigned int comparison
Signed int - unsigned int comparison fixed in mpssd, prctl, ptp, and
timers in Documentation. In places where 'int argc' and 'const char
**argv' are not used, they are replaced with void

Documentation/mic/mpssd/mpssd.c: Fixed comparison in sum_iovec_len and
disp_iovec

Documentation/prctl/disable-tsc-ctxt-sw-stress-test.c: main signature
changed to void, as parameters 'argc' and 'argv' are never used

Documentation/prctl/disable-tsc-on-off-stress-test.c: main signature
changed to void

Documentation/prctl/disable-tsc-test.c: main signature changed to void

Documentation/ptp/testptp.c: Sign comparison fix
Documentation/timers/hpet_example.c: Sign comparision fix

Signed-off-by: Mahesh Khanwalkar <maheshkhanwalkar@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-02-17 14:09:43 -07:00
Michael S. Tsirkin
4e7f9df258 hpet: Drop stale URLs
Looks like the HPET spec at intel.com got moved.
It isn't hard to find so drop the link, just mention
the revision assumed.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1455145462-3877-1-git-send-email-mst@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 09:39:56 +01:00
Paul E. McKenney
c25197841e documentation: Update NO_HZ_FULL interaction with POSIX timers
POSIX timers are no longer starved on adaptive-ticks CPUs.  Instead, they
prevent affected CPUs from entering adaptive-ticks mode.  This commit
therefore updates the NO_HZ.txt documentation.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-02-26 11:57:29 -08:00
Peter Foley
c5e2a7e012 Documentation: update .gitignore files
Add some missing files to .gitignore.
Push Documentation/.gitignore down into subdirectories.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-09-26 11:02:59 +02:00
Peter Foley
df68a01014 Documentation: use subdir-y to avoid unnecessary built-in.o files
Change the Documentation makefiles from obj-m to subdir-y
to avoid generating unnecessary built-in.o files since nothing
in Documentation/ is ever linked in to vmlinux.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-09-26 11:02:55 +02:00
Linus Walleij
7806f60e1d clocksource: document some basic timekeeping concepts
This adds some documentation about clock sources, clock events,
the weak sched_clock() function and delay timers that answers
questions that repeatedly arise on the mailing lists.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Colin Cross <ccross@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:07:13 -07:00
Michael Kerrisk
2779ac167b timer_stats/doc: Fix /proc/timer_stats documentation
Documentation/timers/timer_stats.txt claims:

 "The readout of /proc/timer_stats automatically disables sampling. The sampled
  information is kept until a new sample period is started. This allows multiple
  readouts."

Some simple testing shows that reading from /proc/timer_stats
does not disable sampling. Looking back over past source code,
it appears that it never did.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: http://lkml.kernel.org/r/53636FB6.9060407@gmail.com
[ Small tidyup of the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-04 20:46:32 +02:00
Henrik Austad
3cf8ca1c25 Documentation/: update 00-INDEX files
Some of the 00-INDEX files are somewhat outdated and some folders does
not contain 00-INDEX at all.  Only outdated (with the notably exception
of spi) indexes are touched here, the 169 folders without 00-INDEX has
not been touched.

New 00-INDEX
 - spi/* was added in a series of commits dating back to 2006

Added files (missing in (*/)00-INDEX)
 - dmatest.txt was added by commit 851b7e16a0 ("dmatest: run test via
   debugfs")
 - this_cpu_ops.txt was added by commit a1b2a555d6 ("percpu: add
   documentation on this_cpu operations")
 - ww-mutex-design.txt was added by commit 040a0a3710 ("mutex: Add
   support for wound/wait style locks")
 - bcache.txt was added by commit cafe563591 ("bcache: A block layer
   cache")
 - kernel-per-CPU-kthreads.txt was added by commit 49717cb404
   ("kthread: Document ways of reducing OS jitter due to per-CPU
   kthreads")
 - phy.txt was added by commit ff76496347 ("drivers: phy: add generic
   PHY framework")
 - block/null_blk was added by commit 12f8f4fc03 ("null_blk:
   documentation")
 - module-signing.txt was added by commit 3cafea3076 ("Add
   Documentation/module-signing.txt file")
 - assoc_array.txt was added by commit 3cb989501c ("Add a generic
   associative array implementation.")
 - arm/IXP4xx was part of the initial repo
 - arm/cluster-pm-race-avoidance.txt was added by commit 7fe31d28e8
   ("ARM: mcpm: introduce helpers for platform coherency exit/setup")
 - arm/firmware.txt was added by commit 7366b92a77 ("ARM: Add
   interface for registering and calling firmware-specific operations")
 - arm/kernel_mode_neon.txt was added by commit 2afd0a0524 ("ARM:
   7825/1: document the use of NEON in kernel mode")
 - arm/tcm.txt was added by commit bc581770cf ("ARM: 5580/2: ARM TCM
   (Tightly-Coupled Memory) support v3")
 - arm/vlocks.txt was added by commit 9762f12d3e ("ARM: mcpm: Add
   baremetal voting mutexes")
 - blackfin/gptimers-example.c, Makefile was added by commit
   4b60779d5e ("Blackfin: add an example showing how to use the
   gptimers API")
 - devicetree/usage-model.txt was added by commit 31134efc68 ("dt:
   Linux DT usage model documentation")
 - fb/api.txt was added by commit fb21c2f428 ("fbdev: Add FOURCC-based
   format configuration API")
 - fb/sm501.txt was added by commit e6a0498071 ("video, sm501: add
   edid and commandline support")
 - fb/udlfb.txt was added by commit 96f8d864af ("fbdev: move udlfb out
   of staging.")
 - filesystems/Makefile was added by commit 1e0051ae48
   ("Documentation/fs/: split txt and source files")
 - filesystems/nfs/nfsd-admin-interfaces.txt was added by commit
   8a4c6e19cf ("nfsd: document kernel interfaces for nfsd
   configuration")
 - ide/warm-plug-howto.txt was added by commit f74c91413e ("ide: add
   warm-plug support for IDE devices (take 2)")
 - laptops/Makefile was added by commit d49129accc
   ("Documentation/laptop/: split txt and source files")
 - leds/leds-blinkm.txt was added by commit b54cf35a7f ("LEDS: add
   BlinkM RGB LED driver, documentation and update MAINTAINERS")
 - leds/ledtrig-oneshot.txt was added by commit 5e417281cd ("leds: add
   oneshot trigger")
 - leds/ledtrig-transient.txt was added by commit 44e1e9f8e7 ("leds:
   add new transient trigger for one shot timer activation")
 - m68k/README.buddha was part of the initial repo
 - networking/LICENSE.(qla3xxx|qlcnic|qlge) was added by commits
   40839129f7, c4e84bde1d, 5a4faa8737
 - networking/Makefile was added by commit 3794f3e812 ("docsrc: build
   Documentation/ sources")
 - networking/i40evf.txt was added by commit 105bf2fe6b ("i40evf: add
   driver to kernel build system")
 - networking/ipsec.txt was added by commit b3c6efbc36 ("xfrm: Add
   file to document IPsec corner case")
 - networking/mac80211-auth-assoc-deauth.txt was added by commit
   3cd7920a2b ("mac80211: add auth/assoc/deauth flow diagram")
 - networking/netlink_mmap.txt was added by commit 5683264c39
   ("netlink: add documentation for memory mapped I/O")
 - networking/nf_conntrack-sysctl.txt was added by commit c9f9e0e159
   ("netfilter: doc: add nf_conntrack sysctl api documentation") lan)
 - networking/team.txt was added by commit 3d249d4ca7 ("net: introduce
   ethernet teaming device")
 - networking/vxlan.txt was added by commit d342894c5d ("vxlan:
   virtual extensible lan")
 - power/runtime_pm.txt was added by commit 5e928f77a0 ("PM: Introduce
   core framework for run-time PM of I/O devices (rev.  17)")
 - power/charger-manager.txt was added by commit 3bb3dbbd56
   ("power_supply: Add initial Charger-Manager driver")
 - RCU/lockdep-splat.txt was added by commit d7bd2d68aa ("rcu:
   Document interpretation of RCU-lockdep splats")
 - s390/kvm.txt was added by 5ecee4b (KVM: s390: API documentation)
 - s390/qeth.txt was added by commit b4d72c08b3 ("qeth: bridgeport
   support - basic control")
 - scheduler/sched-bwc.txt was added by commit 88ebc08ea9 ("sched: Add
   documentation for bandwidth control")
 - scsi/advansys.txt was added by commit 4bd6d7f356 ("[SCSI] advansys:
   Move documentation to Documentation/scsi")
 - scsi/bfa.txt was added by commit 1ec90174bd ("[SCSI] bfa: add
   readme file")
 - scsi/bnx2fc.txt was added by commit 12b8fc10ea ("[SCSI] bnx2fc: Add
   driver documentation")
 - scsi/cxgb3i.txt was added by commit c3673464eb ("[SCSI] cxgb3i: Add
   cxgb3i iSCSI driver.")
 - scsi/hpsa.txt was added by commit 992ebcf14f ("[SCSI] hpsa: Add
   hpsa.txt to Documentation/scsi")
 - scsi/link_power_management_policy.txt was added by commit
   ca77329fb7 ("[libata] Link power management infrastructure")
 - scsi/osd.txt was added by commit 78e0c621de ("[SCSI] osd:
   Documentation for OSD library")
 - scsi/scsi-parameter.txt was created/moved by commit 163475fb11
   ("Documentation: move SCSI parameters to their own text file")
 - serial/driver was part of the initial repo
 - serial/n_gsm.txt was added by commit 323e84122e ("n_gsm: add a
   documentation")
 - timers/Makefile was added by commit 3794f3e812 ("docsrc: build
   Documentation/ sources")
 - virt/kvm/s390.txt was added by commit d9101fca3d ("KVM: s390:
   diagnose call documentation")
 - vm/split_page_table_lock was added by commit 49076ec2cc ("mm:
   dynamically allocate page->ptl if it cannot be embedded to struct
   page")
 - w1/slaves/w1_ds28e04 was added by commit fbf7f7b4e2 ("w1: Add
   1-wire slave device driver for DS28E04-100")
 - w1/masters/omap-hdq was added by commit e0a29382c6 ("hdq:
   documentation for OMAP HDQ")
 - x86/early-microcode.txt was added by commit 0d91ea86a8 ("x86, doc:
   Documentation for early microcode loading")
 - x86/earlyprintk.txt was added by commit a1aade4788 ("x86/doc:
   mini-howto for using earlyprintk=dbgp")
 - x86/entry_64.txt was added by commit 8b4777a4b5 ("x86-64: Document
   some of entry_64.S")
 - x86/pat.txt was added by commit d27554d874 ("x86: PAT
   documentation")

Moved files
 - arm/kernel_user_helpers.txt was moved out of arch/arm/kernel by
   commit 37b8304642 ("ARM: kuser: move interface documentation out of
   the source code")
 - efi-stub.txt was moved out of x86/ and down into Documentation/ in
   commit 4172fe2f8a ("EFI stub documentation updates")
 - laptops/hpfall.c was moved out of hwmon/ and into laptops/ in commit
   efcfed9bad ("Move hp_accel to drivers/platform/x86")
 - commit 5616c23ad9 ("x86: doc: move x86-generic documentation from
   Doc/x86/i386"):
   * x86/usb-legacy-support.txt
   * x86/boot.txt
   * x86/zero_page.txt
 - power/video_extension.txt was moved to acpi in commit 70e66e4df1
   ("ACPI / video: move video_extension.txt to Documentation/acpi")

Removed files (left in 00-INDEX)
 - memory.txt was removed by commit 00ea8990aa ("memory.txt: remove
   stray information")
 - gpio.txt was moved to gpio/ in commit fd8e198cfc ("Documentation:
   gpiolib: document new interface")
 - networking/DLINK.txt was removed by commit 168e06ae26
   ("drivers/net: delete old parallel port de600/de620 drivers")
 - serial/hayes-esp.txt was removed by commit f53a2ade0b ("tty: esp:
   remove broken driver")
 - s390/TAPE was removed by commit 9e280f6693 ("[S390] remove tape
   block docu")
 - vm/locking was removed by commit 57ea8171d2 ("mm: documentation:
   remove hopelessly out-of-date locking doc")
 - laptops/acer-wmi.txt was remvoed by commit 020036678e ("acer-wmi:
   Delete out-of-date documentation")

Typos/misc issues
 - rpc-server-gss.txt was added as knfsd-rpcgss.txt in commit
   030d794bf4 ("SUNRPC: Use gssproxy upcall for server RPCGSS
   authentication.")
 - commit b88cf73d92 ("net: add missing entries to
   Documentation/networking/00-INDEX")
   * generic-hdlc.txt was added as generic_hdlc.txt
   * spider_net.txt was added as spider-net.txt
 - w1/master/mxc-w1 was added as mxc_w1 by commit a5fd9139f7 ("w1: add
   1-wire master driver for i.MX27 / i.MX31")
 - s390/zfcpdump.txt was added as zfcpdump by commit 6920c12a40
   ("[S390] Add Documentation/s390/00-INDEX.")

Signed-off-by: Henrik Austad <henrik@austad.us>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>	[rcu bits]
Acked-by: Rob Landley <rob@landley.net>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Len Brown <len.brown@intel.com>
Cc: James Bottomley <JBottomley@parallels.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-10 16:01:40 -08:00
Henrik Austad
ebd46f016a doc: add missing files to timers/00-INDEX
- timers-howto was added by commit 0fcb8081 (Documentation: Add
  timers/timers-howto.txt)
- NO_HZ was added by commit 0c87f9b5 (nohz_full: Add documentation.)

Cc: Patrick Pannuto <ppannuto@codeaurora.org>
Signed-off-by: Henrik Austad <haustad@cisco.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-10-27 21:55:50 +00:00
Paul E. McKenney
8bdf7a252b nohz_full: Add testing information to documentation
This commit adds information about testing nohz_full, and also emphasizes
the fact that you need a multi-CPU system to get any benefit from nohz_full.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-08-18 18:06:55 -07:00
Paul E. McKenney
ce5f4fc861 nohz_full: Document additional restrictions
This commit calls out the potential for slowing the tick even when there
are multiple runnable processes per CPU,  It also points out that current
mainlined version keeps the tick going on at least one CPU even when all
CPUs are otherwise idle.  Finally, it notes the need for a 1-HZ tick in
order to calculate CPU load, maintain sched average, compute CFS entity
vruntime, compute avenrun, and carry out load balancing.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:42:38 -07:00
Paul E. McKenney
295fde89be nohz_full: Update based on Sedat Dilek review
Make it more clear that there are three options, and give hints as
to which of the three is most likely to be useful in different
situations.

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-06-10 13:42:37 -07:00
Paul E. McKenney
0c87f9b5ca nohz_full: Add documentation.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Olivier Baetz <olivier.baetz@novasparks.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
2013-04-27 16:41:43 -07:00
Paul Bolle
395cf9691d doc: fix broken references
There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-09-27 18:08:04 +02:00
Jonathan Neuschäfer
049262940e doc: timers-howto: fix a typo ("unsgined")
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-17 10:52:02 +02:00
Uwe Kleine-König
b595076a18 tree-wide: fix comment/printk typos
"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-01 15:38:34 -04:00
Jaswinder Singh Rajput
aaaddfe0b3 Documentation/timers/hpet_example.c: add supporting info for hpet_example
$./hpet_example info /dev/hpet
-hpet: executing info
hpet_info: hi_irqfreq 0x0 hi_flags 0x0 hi_hpet 0 hi_timer 2

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: "Venkatesh Pallipadi (Venki)" <venki@google.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:11 -07:00
Patrick Pannuto
0fcb80818b Documentation: Add timers/timers-howto.txt
This file seeks to explain the nuances in various delays;
many driver writers are not necessarily familiar with the
various kernel timers, their shortfalls, and quirks. When
faced with

ndelay, udelay, mdelay, usleep_range, msleep, and msleep_interrubtible

the question "How do I just wait 1 ms for my hardware to
latch?" has the non-intuitive "best" answer:
	usleep_range(1000,1500)

This patch is followed by a series of checkpatch additions
that seek to help kernel hackers pick the best delay.

Signed-off-by: Patrick Pannuto <ppannuto@codeaurora.org>
Cc: apw@canonical.com
Cc: corbet@lwn.net
Cc: arjan@linux.intel.com
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1280786467-26999-3-git-send-email-ppannuto@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-08-04 11:00:45 +02:00
Randy Dunlap
0a6531ebea Documentation/timers/hpet_example.c: only build on X86
We should only build hpet_example on x86[-64], where it is implemented.
It can cause build errors on other architectures.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-01 10:05:19 -07:00
Andrea Gelmini
4164fcc2f9 Documentation/timers/hpet_example: drop duplicate header files
Documentation/timers/hpet_example.c: fcntl.h is included more than once.
Documentation/timers/hpet_example.c: signal.h is included more than once.

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-24 07:30:56 -07:00
Randy Dunlap
e61863099f Documentation/timers/: split txt and source files
Documentation/timers/hpet.txt:
Expose example and tool source files in the Documentation/timers/ directory in
their own files instead of being buried (almost hidden) in readme/txt files.
This should help to prevent bitrot.

This will make them more visible/usable to users who may need
to use them, to developers who may need to test with them, and
to anyone who would fix/update them if they were more visible.

Also, if any of these possibly should not be in the kernel tree at
all, it will be clearer that they are here and we can discuss if
they should be removed.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:35 -08:00
Amerigo Wang
1039c6ba67 fix URL in hpet.txt
That URL is out of date. Update it.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Matt LaPlante <kernel1@cyberdogtech.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: WANG Cong <amwang@redhat.com>
Acked-by: Matt LaPlante <kernel@cyberdogtech.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-09 09:40:54 +01:00
Matt LaPlante
19f5946001 trivial: Miscellaneous documentation typo fixes
Fix various typos in documentation txts.

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-06-12 18:01:47 +02:00
David Brownell
64a76f667d hpet: /dev/hpet - fixes and cleanup
Minor /dev/hpet updates and bugfixes:

  * Remove dead code, mostly remnants of an incomplete/unusable
    kernel interface ... noted when addressing "sparse" warnings:
      + hpet_unregister() and a routine it calls
      + hpet_task and all references, including hpet_task_lock
      + hpet_data.hd_flags (and HPET_DATA_PLATFORM)

  * Correct and improve boot message:
      + displays *counter* (shared between comparators) bit width,
        not *timer* bit widths (which are often mixed)
      + relabel "timers" as "comparators"; this is less confusing,
        they are not independent like normal timers are (sigh)
      + display MHz not Hz; it's never less than 10 MHz.

  * Tighten and correct the userspace interface code
      + don't accidentally program comparators in 64-bit mode using
        32-bit values ... always force comparators into 32-bit mode
      + provide the correct bit definition flagging comparators with
        periodic capability ... the ABI is unchanged

  * Update Documentation/hpet.txt
      + be more correct and current
      + expand description a bit
      + don't mention that now-gone kernel interface

Plus, add a FIXME comment for something that could cause big trouble
on systems with more capable HPETs than at least Intel seems to ship.

It seems that few folk use this userspace interface; it's not very
usable given the general lack of HPET IRQ routing.  I'm told that
the only real point of it any more is to mmap for fast timestamps;
IMO that's handled better through the gettimeofday() vsyscall.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-31 18:45:41 +02:00
Ingo Molnar
85e9ca333d Merge branch 'linus' into timers/hpet 2008-07-31 18:43:41 +02:00