diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2011-10-05 11:59:38 -0700 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-02-15 10:32:55 -0600 |
| commit | 2bcefa5a6b93933dc4c4c6f1a368628f72e3efae (patch) | |
| tree | e5969aa3083b51aca3ac04f9b714cf398d8004ab /virt | |
| parent | fdc84993bb79a39c09672b6e955f917708ecb789 (diff) | |
rcu: Merge RCU-bh into RCU-preempt
The Linux kernel has long RCU-bh read-side critical sections that
intolerably increase scheduling latency under mainline's RCU-bh rules,
which include RCU-bh read-side critical sections being non-preemptible.
This patch therefore arranges for RCU-bh to be implemented in terms of
RCU-preempt for CONFIG_PREEMPT_RT_FULL=y.
This has the downside of defeating the purpose of RCU-bh, namely,
handling the case where the system is subjected to a network-based
denial-of-service attack that keeps at least one CPU doing full-time
softirq processing. This issue will be fixed by a later commit.
The current commit will need some work to make it appropriate for
mainline use, for example, it needs to be extended to cover Tiny RCU.
[ paulmck: Added a useful changelog ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20111005185938.GA20403@linux.vnet.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions