linux.git/kernel/rcu/tree_exp.h, branch v4.20

rcu: Switch ->dynticks to rcu_data structure, remove rcu_dynticks

2018-08-30T23:03:52+00:00

This commit move ->dynticks from the rcu_dynticks structure to the
rcu_data structure, replacing the field of the same name.  It also updates
the code to access ->dynticks from the rcu_data structure and to use the
rcu_data structure rather than following to now-gone ->dynticks field
to the now-gone rcu_dynticks structure.  While in the area, this commit
also fixes up comments.

Signed-off-by: Paul E. McKenney

rcu: Switch urgent quiescent-state requests to rcu_data structure

2018-08-30T23:03:50+00:00

This commit removes ->rcu_need_heavy_qs and ->rcu_urgent_qs from the
rcu_dynticks structure and updates the code to access them from the
rcu_data structure.

Signed-off-by: Paul E. McKenney

rcu: Avoid resched_cpu() when rescheduling the current CPU

2018-08-30T23:03:45+00:00

The resched_cpu() interface is quite handy, but it does acquire the
specified CPU's runqueue lock, which does not come for free.  This
commit therefore substitutes the following when directing resched_cpu()
at the current CPU:

	set_tsk_need_resched(current);
	set_preempt_need_resched();

Signed-off-by: Paul E. McKenney 
Cc: Peter Zijlstra

rcu: Clean up flavor-related definitions and comments in tree_exp.h

2018-08-30T23:03:35+00:00

Signed-off-by: Paul E. McKenney

rcu: Remove rsp parameter from rcu_node tree accessor macros

2018-08-30T23:03:16+00:00

There now is only one rcu_state structure in a given build of the Linux
kernel, so there is no need to pass it as a parameter to RCU's rcu_node
tree's accessor macros.  This commit therefore removes the rsp parameter
from those macros in kernel/rcu/rcu.h, and removes some now-unused rsp
local variables while in the area.

Signed-off-by: Paul E. McKenney

rcu: Remove rsp parameter from expedited grace-period functions

2018-08-30T23:03:14+00:00

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to
RCU's functions.  This commit therefore removes the rsp parameter
from the code in kernel/rcu/tree_exp.h, and removes all of the
rsp local variables while in the area.

Signed-off-by: Paul E. McKenney

rcu: Remove rsp parameter from rcu_get_root()

2018-08-30T23:02:55+00:00

There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions.  This commit therefore removes the rsp parameter from
rcu_get_root().

Signed-off-by: Paul E. McKenney

rcu: Remove rcu_state_p pointer to default rcu_state structure

2018-08-30T23:02:50+00:00

The rcu_state_p pointer references the default rcu_state structure,
that is, the one that call_rcu() uses, as opposed to call_rcu_bh()
and sometimes call_rcu_sched().  But there is now only one rcu_state
structure, so that one structure is by definition the default, which
means that the rcu_state_p pointer no longer serves any useful purpose.
This commit therefore removes it.

Signed-off-by: Paul E. McKenney

rcu: Remove rcu_state structure's ->rda field

2018-08-30T23:02:49+00:00

The rcu_state structure's ->rda field was used to find the per-CPU
rcu_data structures corresponding to that rcu_state structure.  But now
there is only one rcu_state structure (creatively named "rcu_state")
and one set of per-CPU rcu_data structures (creatively named "rcu_data").
Therefore, uses of the ->rda field can always be replaced by "rcu_data,
and this commit makes that change and removes the ->rda field.

Signed-off-by: Paul E. McKenney

rcu: Eliminate rcu_state structure's ->call field

2018-08-30T23:02:48+00:00

The rcu_state structure's ->call field references the corresponding RCU
flavor's call_rcu() function.  However, now that there is only ever one
rcu_state structure in a given build of the Linux kernel, and that flavor
uses plain old call_rcu(), there is not a lot of point in continuing to
have the ->call field.  This commit therefore removes it.

Signed-off-by: Paul E. McKenney