user/sven/linux.git/kernel/rcutiny.c, branch v3.2

kernel: fix up module header handling in rcutiny files

2011-10-31T13:20:13Z

The file rcutiny.c does not need moduleparam.h header, as there are no modparams in this file. However rcutiny_plugin.h does define a module_init() and a module_exit() and it uses the various MODULE_ macros, so it really does need module.h included. Signed-off-by: Paul Gortmaker

kernel: Map most files to use export.h instead of module.h

2011-10-31T13:20:12Z

The changed files were only including linux/module.h for the EXPORT_SYMBOL infrastructure, and nothing else. Revector them onto the isolated export header for faster compile times. Nothing to see here but a whole lot of instances of: -#include +#include This commit is only changing the kernel dir; next targets will probably be mm, fs, the arch dirs, etc. Signed-off-by: Paul Gortmaker

rcu: Add grace-period, quiescent-state, and call_rcu trace events

2011-09-29T04:38:21Z

Add trace events to record grace-period start and end, quiescent states, CPUs noticing grace-period start and end, grace-period initialization, call_rcu() invocation, tasks blocking in RCU read-side critical sections, tasks exiting those same critical sections, force_quiescent_state() detection of dyntick-idle and offline CPUs, CPUs entering and leaving dyntick-idle mode (except from NMIs), CPUs coming online and going offline, and CPUs being kicked for staying in dyntick-idle mode for too long (as in many weeks, even on 32-bit systems). Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney rcu: Add the rcu flavor to callback trace events The earlier trace events for registering RCU callbacks and for invoking them did not include the RCU flavor (rcu_bh, rcu_preempt, or rcu_sched). This commit adds the RCU flavor to those trace events. Signed-off-by: Paul E. McKenney

rcu: Make TINY_RCU also use softirq for RCU_BOOST=n

2011-09-29T04:38:20Z

This patch #ifdefs TINY_RCU kthreads out of the kernel unless RCU_BOOST=y, thus eliminating context-switch overhead if RCU priority boosting has not been configured. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney

rcu: Add RCU type to callback-invocation tracing

2011-09-29T04:38:15Z

Add a string to the rcu_batch_start() and rcu_batch_end() trace messages that indicates the RCU type ("rcu_sched", "rcu_bh", or "rcu_preempt"). The trace messages for the actual invocations themselves are not marked, as it should be clear from the rcu_batch_start() and rcu_batch_end() events before and after. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney

rcu: Put names into TINY_RCU structures under RCU_TRACE

2011-09-29T04:38:14Z

In order to allow event tracing to distinguish between flavors of RCU, we need those names in the relevant RCU data structures. TINY_RCU has avoided them for memory-footprint reasons, so add them only if CONFIG_RCU_TRACE=y. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney

rcu: Add event-tracing for RCU callback invocation

2011-09-29T04:38:12Z

There was recently some controversy about the overhead of invoking RCU callbacks. Add TRACE_EVENT()s to obtain fine-grained timings for the start and stop of a batch of callbacks and also for each callback invoked. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney

rcu: Abstract common code for RCU grace-period-wait primitives

2011-09-29T04:36:42Z

Pull the code that waits for an RCU grace period into a single function, which is then called by synchronize_rcu() and friends in the case of TREE_RCU and TREE_PREEMPT_RCU, and from rcu_barrier() and friends in the case of TINY_RCU and TINY_PREEMPT_RCU. Signed-off-by: Paul E. McKenney

sanitize usage

2011-05-20T19:50:29Z

Commit e66eed651fd1 ("list: remove prefetching from regular list iterators") removed the include of prefetch.h from list.h, which uncovered several cases that had apparently relied on that rather obscure header file dependency. So this fixes things up a bit, using grep -L linux/prefetch.h $(git grep -l '[^a-z_]prefetchw*(' -- '*.[ch]') grep -L 'prefetchw*(' $(git grep -l 'linux/prefetch.h' -- '*.[ch]') to guide us in finding files that either need inclusion, or have it despite not needing it. There are more of them around (mostly network drivers), but this gets many core ones. Reported-by: Stephen Rothwell Signed-off-by: Linus Torvalds

rcu: optimize rcutiny

2011-05-06T06:16:59Z

rcu_sched_qs() currently calls local_irq_save()/local_irq_restore() up to three times. Remove irq masking from rcu_qsctr_help() / invoke_rcu_kthread() and do it once in rcu_sched_qs() / rcu_bh_qs() This generates smaller code as well. text data bss dec hex filename 2314 156 24 2494 9be kernel/rcutiny.old.o 2250 156 24 2430 97e kernel/rcutiny.new.o Fix an outdated comment for rcu_qsctr_help() Move invoke_rcu_kthread() definition before its use. Signed-off-by: Eric Dumazet Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett