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2017-06-09rcu: Eliminate NOCBs CPU-state Kconfig optionsPaul E. McKenney1-26/+3
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>
2015-02-26documentation: Update NO_HZ_FULL interaction with POSIX timersPaul E. McKenney1-7/+3
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>
2013-08-19nohz_full: Add testing information to documentationPaul E. McKenney1-10/+34
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>
2013-06-11nohz_full: Document additional restrictionsPaul E. McKenney1-3/+18
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>
2013-06-11nohz_full: Update based on Sedat Dilek reviewPaul E. McKenney1-9/+49
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>
2013-04-28nohz_full: Add documentation.Paul E. McKenney1-0/+273
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>