linux/kernel/rcupdate.c, branch v2.6.25

rcupdate: fix comment

2008-02-14T00:21:18Z

This comment caused some consternation during fastcall removal. Make it truthful. Signed-off-by: Paul E. McKenney Cc: Harvey Harrison Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Preempt-RCU: fix rcu_barrier for preemptive environment.

2008-01-25T20:08:24Z

Fix rcu_barrier() to work properly in preemptive kernel environment. Also, the ordering of callback must be preserved while moving callbacks to another CPU during CPU hotplug. 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

Preempt-RCU: reorganize RCU code into rcuclassic.c and rcupdate.c

2008-01-25T20:08:24Z

This patch re-organizes the RCU code to enable multiple implementations of RCU. Users of RCU continues to include rcupdate.h and the RCU interfaces remain the same. This is in preparation for subsequently merging the preemptible RCU implementation. 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

Preempt-RCU: Use softirq instead of tasklets for

2008-01-25T20:08:23Z

This patch makes RCU use softirq instead of tasklets. It also adds a memory barrier after raising the softirq inorder to ensure that the cpu sees the most recently updated value of rcu->cur while processing callbacks. The discussion of the related theoretical race pointed out by James Huang can be found here --> http://lkml.org/lkml/2007/11/20/603 Signed-off-by: Gautham R Shenoy Signed-off-by: Steven Rostedt Signed-off-by: Dipankar Sarma Reviewed-by: Steven Rostedt Signed-off-by: Ingo Molnar

rcu: fix section mismatch

2008-01-22T17:17:48Z

rcu_online_cpu() should be __cpuinit instead of __devinit. WARNING: vmlinux.o(.text+0x4b6d5): Section mismatch: reference to .init.text: (between 'rcu_cpu_notify' and 'wakeme_after_rcu') Signed-off-by: Randy Dunlap Cc: Sam Ravnborg Acked-by: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Clean up duplicate includes in kernel/

2007-10-17T15:42:48Z

This patch cleans up duplicate includes in kernel/ Signed-off-by: Jesper Juhl Acked-by: Paul E. McKenney Reviewed-by: Satyam Sharma Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lockdep: annotate rcu_read_{,un}lock{,_bh}

2007-10-11T20:11:12Z

lockdep annotate rcu_read_{,un}lock{,_bh} in order to catch imbalanced usage. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar Cc: Paul E. McKenney

Add suspend-related notifications for CPU hotplug

2007-05-09T19:30:56Z

Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki Cc: Gautham R Shenoy Cc: Pavel Machek Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] rcu: add a prefetch() in rcu_do_batch()

2006-12-07T16:39:40Z

On some workloads, (for example when lot of close() syscalls are done), RCU qlen can be quite large, and RCU heads are no longer in cpu cache when rcu_do_batch() is called. This patch adds a prefetch() in rcu_do_batch() to give CPU a hint to bring back cache lines containing 'struct rcu_head's. Most list manipulations macros include prefetch(), but not open coded ones (at least with current C compilers :) ) I got a nice speedup on a trivial benchmark (3.48 us per iteration instead of 3.95 us on a 1.6 GHz Pentium-M) while (1) { pipe(p); close(fd[0]); close(fd[1]);} Signed-off-by: Eric Dumazet Cc: "Paul E. McKenney" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] rcu: simplify/improve batch tuning

2006-10-04T14:55:31Z

Kill a hard-to-calculate 'rsinterval' boot parameter and per-cpu rcu_data.last_rs_qlen. Instead, it adds adds a flag rcu_ctrlblk.signaled, which records the fact that one of CPUs has sent a resched IPI since the last rcu_start_batch(). Roughly speaking, we need two rcu_start_batch()s in order to move callbacks from ->nxtlist to ->donelist. This means that when ->qlen exceeds qhimark and continues to grow, we should send a resched IPI, and then do it again after we gone through a quiescent state. On the other hand, if it was already sent, we don't need to do it again when another CPU detects overflow of the queue. Signed-off-by: Oleg Nesterov Acked-by: Paul E. McKenney Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds