From e260be673a15b6125068270e0216a3bfbfc12f87 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 25 Jan 2008 21:08:24 +0100 Subject: Preempt-RCU: implementation This patch implements a new version of RCU which allows its read-side critical sections to be preempted. It uses a set of counter pairs to keep track of the read-side critical sections and flips them when all tasks exit read-side critical section. The details of this implementation can be found in this paper - http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf and the article- http://lwn.net/Articles/253651/ This patch was developed as a part of the -rt kernel development and meant to provide better latencies when read-side critical sections of RCU don't disable preemption. As a consequence of keeping track of RCU readers, the readers have a slight overhead (optimizations in the paper). This implementation co-exists with the "classic" RCU implementations and can be switched to at compiler. Also includes RCU tracing summarized in debugfs. [ akpm@linux-foundation.org: build fixes on non-preempt architectures ] Signed-off-by: Gautham R Shenoy Signed-off-by: Dipankar Sarma Signed-off-by: Paul E. McKenney Reviewed-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/Makefile | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'kernel/Makefile') diff --git a/kernel/Makefile b/kernel/Makefile index def5dd6097a0..68755cd9a7e4 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -6,7 +6,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \ exit.o itimer.o time.o softirq.o resource.o \ sysctl.o capability.o ptrace.o timer.o user.o user_namespace.o \ signal.o sys.o kmod.o workqueue.o pid.o \ - rcupdate.o rcuclassic.o extable.o params.o posix-timers.o \ + rcupdate.o extable.o params.o posix-timers.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o latency.o nsproxy.o srcu.o \ utsname.o notifier.o @@ -52,6 +52,11 @@ obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ obj-$(CONFIG_SECCOMP) += seccomp.o obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o +obj-$(CONFIG_CLASSIC_RCU) += rcuclassic.o +obj-$(CONFIG_PREEMPT_RCU) += rcupreempt.o +ifeq ($(CONFIG_PREEMPT_RCU),y) +obj-$(CONFIG_RCU_TRACE) += rcupreempt_trace.o +endif obj-$(CONFIG_RELAY) += relay.o obj-$(CONFIG_SYSCTL) += utsname_sysctl.o obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o -- cgit v1.2.2