rcu: Stop disabling interrupts in scheduler fastpaths

Browse source

We need the scheduler's fastpaths to be, well, fast, and unnecessarily
disabling and re-enabling interrupts is not necessarily consistent with
this goal.  Especially given that there are regions of the scheduler that
already have interrupts disabled.

This commit therefore moves the call to rcu_note_context_switch()
to one of the interrupts-disabled regions of the scheduler, and
removes the now-redundant disabling and re-enabling of interrupts from
rcu_note_context_switch() and the functions it calls.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Shift rcu_note_context_switch() to avoid deadlock, as suggested
  by Peter Zijlstra. ]

...

This commit is contained in:

Paul E. McKenney 2015-10-07 09:10:48 -07:00

parent f0f2e7d307

commit 46a5d164db

4 changed files with 23 additions and 26 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

2

include/linux/rcutree.h

View file

27

kernel/rcu/tree.c

View file

14

kernel/rcu/tree_plugin.h

View file

6

kernel/sched/core.c

View file