kernel/linux.git/Documentation/timers, branch v6.1.168

Documentation: Replace del_timer/del_timer_sync()

2025-10-29T13:04:32+00:00

[ Upstream commit 87bdd932e85881895d4720255b40ac28749c4e32 ] Adjust to the new preferred function names. Suggested-by: Steven Rostedt Signed-off-by: Thomas Gleixner Reviewed-by: Jacob Keller Reviewed-by: Anna-Maria Behnsen Link: https://lore.kernel.org/r/20221123201625.075320635@linutronix.de Signed-off-by: Jeongjun Park Signed-off-by: Greg Kroah-Hartman

sched/isolation: Prevent boot crash when the boot CPU is nohz_full

2025-03-28T20:58:48+00:00

Documentation/timers/no_hz.rst states that the "nohz_full=" mask must not include the boot CPU, which is no longer true after: 08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full"). However after: aae17ebb53cd ("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). [ Apply only documentation changes as commit which causes boot crash when boot CPU is nohz_full is not backported to stable kernels - Krishanth ] Reported-by: Chris von Recklinghausen Signed-off-by: Oleg Nesterov Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Reviewed-by: Phil Auld Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20240411143905.GA19288@redhat.com Closes: https://lore.kernel.org/all/20240402105847.GA24832@redhat.com/ Signed-off-by: Krishanth Jagaduri [ strip out upstream commit and Fixes: so tools don't get confused that this commit actually does anything real - gregkh] Signed-off-by: Greg Kroah-Hartman

rcu: Remove the RCU_FAST_NO_HZ Kconfig option

2021-12-01T01:24:47+00:00

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

Documentation/no_hz: Introduce "dyntick-idle mode" before using it

2021-09-27T17:31:11+00:00

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 Link: https://lore.kernel.org/r/20210914203355.21360-1-bp@alien8.de Signed-off-by: Jonathan Corbet

Documentation: drop optional BOMs

2021-05-10T21:17:34+00:00

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 Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Greg Kroah-Hartman Cc: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/20210506231907.14359-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet

Documentation: Replace lkml.org links with lore

2021-01-11T19:47:38+00:00

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 Link: https://lore.kernel.org/r/77cdb7f32cfb087955bfc3600b86c40bed5d4104.camel@perches.com Signed-off-by: Jonathan Corbet

docs: timers: drop documentation about LB_BIAS

2020-07-23T20:32:44+00:00

The LB_BIAS feature was removed in commit 1c1b8a7b03ef ("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 Link: https://lore.kernel.org/r/1595088518-28116-1-git-send-email-Julia.Lawall@inria.fr Signed-off-by: Jonathan Corbet

timer: add fsleep for flexible sleeping

2020-05-07T00:03:34+00:00

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 Signed-off-by: David S. Miller

docs: add some directories to the main documentation index

2019-07-15T14:03:03+00:00

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 Acked-by: Bartlomiej Zolnierkiewicz

docs: timers: convert docs to ReST and rename to *.rst

2019-06-14T20:31:48+00:00

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 Acked-by: Mark Brown Signed-off-by: Jonathan Corbet