linux-stable.git/include/linux/rcutree.h, branch v4.18.2

rcu/x86: Provide early rcu_cpu_starting() callback

2018-05-22T23:12:26+00:00

The x86/mtrr code does horrific things because hardware. It uses
stop_machine_from_inactive_cpu(), which does a wakeup (of the stopper
thread on another CPU), which uses RCU, all before the CPU is onlined.

RCU complains about this, because wakeups use RCU and RCU does
(rightfully) not consider offline CPUs for grace-periods.

Fix this by initializing RCU way early in the MTRR case.

Tested-by: Mike Galbraith 
Signed-off-by: Peter Zijlstra 
Signed-off-by: Paul E. McKenney 
[ paulmck: Add !SMP support, per 0day Test Robot report. ]

rcu: Declare rcu_eqs_special_set() in public header

2018-05-15T17:27:51+00:00

Because rcu_eqs_special_set() is declared only in internal header
kernel/rcu/tree.h and stubbed in include/linux/rcutiny.h, it is
inaccessible outside of the RCU implementation.  This patch therefore
moves the  rcu_eqs_special_set() declaration to include/linux/rcutree.h,
which allows it to be used in non-rcu kernel code.

Signed-off-by: Yury Norov 
Signed-off-by: Paul E. McKenney 
Tested-by: Nicholas Piggin

rcu: Eliminate rcu_irq_enter_disabled()

2017-11-27T16:42:03+00:00

Now that the irq path uses the rcu_nmi_{enter,exit}() algorithm,
rcu_irq_enter() and rcu_irq_exit() may be used from any context.  There is
thus no need for rcu_irq_enter_disabled() and for the checks using it.
This commit therefore eliminates rcu_irq_enter_disabled().

Signed-off-by: Paul E. McKenney

rcu: Remove #ifdef moving rcu_end_inkernel_boot from rcupdate.h

2017-06-09T01:52:40+00:00

This commit removes a #ifdef and saves a few lines of code by moving
the rcu_end_inkernel_boot() function from include/linux/rcupdate.h to
include/linux/rcutiny.h (for TINY_RCU) and to include/linux/rcutree.h
(for TREE_RCU).

Signed-off-by: Paul E. McKenney

rcu: Move rcu_request_urgent_qs_task() out of rcutiny.h and rcutree.h

2017-06-09T01:52:33+00:00

The rcu_request_urgent_qs_task() function is used only within RCU,
so there is no point in exporting it to the rest of the kernel from
nclude/linux/rcutiny.h and include/linux/rcutree.h.  This commit therefore
moves this function to kernel/rcu/rcu.h.

Reported-by: Ingo Molnar 
Signed-off-by: Paul E. McKenney

rcu: Move torture-related functions out of rcutiny.h and rcutree.h

2017-06-09T01:52:33+00:00

The various functions similar to rcu_batches_started(), the
function show_rcu_gp_kthreads(), the various functions similar to
rcu_force_quiescent_state(), and the variables rcutorture_testseq and
rcutorture_vernum are used only within RCU.  There is therefore no point
in exporting them to the kernel at large from include/linux/rcutiny.h
and include/linux/rcutree.h.  This commit therefore moves all of these
to kernel/rcu/rcu.h.

Reported-by: Ingo Molnar 
Signed-off-by: Paul E. McKenney

rcu: Move torture-related definitions from rcupdate.h to rcu.h

2017-06-09T01:52:28+00:00

The include/linux/rcupdate.h file contains a number of definitions that
are used only to communicate between rcutorture, rcuperf, and the RCU code
itself.  There is no point in having these definitions exposed globally
throughout the kernel, so this commit moves them to kernel/rcu/rcu.h.
This change has the added benefit of shrinking rcupdate.h.

Reported-by: Ingo Molnar 
Signed-off-by: Paul E. McKenney

rcu: Make non-preemptive schedule be Tasks RCU quiescent state

2017-04-21T12:59:27+00:00

Currently, a call to schedule() acts as a Tasks RCU quiescent state
only if a context switch actually takes place.  However, just the
call to schedule() guarantees that the calling task has moved off of
whatever tracing trampoline that it might have been one previously.
This commit therefore plumbs schedule()'s "preempt" parameter into
rcu_note_context_switch(), which then records the Tasks RCU quiescent
state, but only if this call to schedule() was -not- due to a preemption.

To avoid adding overhead to the common-case context-switch path,
this commit hides the rcu_note_context_switch() check under an existing
non-common-case check.

Suggested-by: Steven Rostedt 
Signed-off-by: Paul E. McKenney

rcu: Convert rcutree to hotplug state machine

2016-07-15T08:41:44+00:00

Straight forward conversion to the state machine. Though the question arises
whether this needs really all these state transitions to work.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anna-Maria Gleixner 
Reviewed-by: Sebastian Andrzej Siewior 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153337.982013161@linutronix.de
Signed-off-by: Ingo Molnar

rcutorture: Expedited-GP batch progress access to torturing

2016-03-31T20:37:37+00:00

This commit provides rcu_exp_batches_completed() and
rcu_exp_batches_completed_sched() functions to allow torture-test modules
to check how many expedited grace period batches have completed.
These are analogous to the existing rcu_batches_completed(),
rcu_batches_completed_bh(), and rcu_batches_completed_sched() functions.

Signed-off-by: Paul E. McKenney