user/sven/linux.git/kernel/rcupdate.c, branch v3.12.6

Merge tag 'trace-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-09-09T21:42:15Z

Pull tracing updates from Steven Rostedt: "Not much changes for the 3.12 merge window. The major tracing changes are still in flux, and will have to wait for 3.13. The changes for 3.12 are mostly clean ups and minor fixes. H Peter Anvin added a check to x86_32 static function tracing that helps a small segment of the kernel community. Oleg Nesterov had a few changes from 3.11, but were mostly clean ups and not worth pushing in the -rc time frame. Li Zefan had small clean up with annotating a raw_init with __init. I fixed a slight race in updating function callbacks, but the race is so small and the bug that happens when it occurs is so minor it's not even worth pushing to stable. The only real enhancement is from Alexander Z Lam that made the tracing_cpumask work for trace buffer instances, instead of them all sharing a global cpumask" * tag 'trace-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace/rcu: Do not trace debug_lockdep_rcu_enabled() x86-32, ftrace: Fix static ftrace when early microcode is enabled ftrace: Fix a slight race in modifying what function callback gets traced tracing: Make tracing_cpumask available for all instances tracing: Kill the !CONFIG_MODULES code in trace_events.c tracing: Don't pass file_operations array to event_create_dir() tracing: Kill trace_create_file_ops() and friends tracing/syscalls: Annotate raw_init function with __init

ftrace/rcu: Do not trace debug_lockdep_rcu_enabled()

2013-09-05T13:31:33Z

The function debug_lockdep_rcu_enabled() is part of the RCU lockdep debugging, and is called very frequently. I found that if I enable a lot of debugging and run the function graph tracer, this function can cause a live lock of the system. We don't usually trace lockdep infrastructure, no need to trace this either. Reviewed-by: Paul E. McKenney Signed-off-by: Steven Rostedt

rcu: Simplify debug-objects fixups

2013-08-19T00:39:45Z

The current debug-objects fixups are complex and heavyweight, and the fixups are not complete: Even with the fixups, RCU's callback lists can still be corrupted. This commit therefore strips the fixups down to their minimal form, eliminating two of the three. It would be even better if (for example) call_rcu() simply leaked any problematic callbacks, but for that to happen, the debug-objects system would need to inform its caller of suspicious situations. This is the subject of a later commit in this series. Signed-off-by: Paul E. McKenney Cc: Mathieu Desnoyers Cc: Sedat Dilek Cc: Davidlohr Bueso Cc: Rik van Riel Cc: Thomas Gleixner Cc: Linus Torvalds Tested-by: Sedat Dilek Reviewed-by: Josh Triplett

rcu: Add const annotation to char * for RCU tracepoints and functions

2013-07-29T21:07:49Z

All the RCU tracepoints and functions that reference char pointers do so with just 'char *' even though they do not modify the contents of the string itself. This will cause warnings if a const char * is used in one of these functions. The RCU tracepoints store the pointer to the string to refer back to them when the trace output is displayed. As this can be minutes, hours or even days later, those strings had better be constant. This change also opens the door to allow the RCU tracepoint strings and their addresses to be exported so that userspace tracing tools can translate the contents of the pointers of the RCU tracepoints. Signed-off-by: Steven Rostedt

Merge branches 'cbnum.2013.06.10a', 'doc.2013.06.10a', 'fixes.2013.06.10a', 'srcu.2013.06.10a' and 'tiny.2013.06.10a' into HEAD

2013-06-10T20:46:44Z

cbnum.2013.06.10a: Apply simplifications stemming from the new callback numbering. doc.2013.06.10a: Documentation updates. fixes.2013.06.10a: Miscellaneous fixes. srcu.2013.06.10a: Updates to SRCU. tiny.2013.06.10a: Eliminate TINY_PREEMPT_RCU.

rcu: Shrink TINY_RCU by moving exit_rcu()

2013-06-10T20:45:52Z

Now that TINY_PREEMPT_RCU is no more, exit_rcu() is always an empty function. But if TINY_RCU is going to have an empty function, it should be in include/linux/rcutiny.h, where it does not bloat the kernel. This commit therefore moves exit_rcu() out of kernel/rcupdate.c to kernel/rcutree_plugin.h, and places a static inline empty function in include/linux/rcutiny.h in order to shrink TINY_RCU a bit. Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett

rcu: Merge adjacent identical ifdefs

2013-06-10T20:44:56Z

Two ifdefs in kernel/rcupdate.c now have identical conditions with nothing between them, so the commit merges them into a single ifdef. Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett

Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD

2013-01-29T06:25:21Z

doctorture.2013.01.11a: Changes to rcutorture and to RCU documentation. fixes.2013.01.26a: Miscellaneous fixes. tagcb.2013.01.24a: Tag RCU callbacks with grace-period number to simplify callback advancement. tiny.2013.01.29b: Enhancements to uniprocessor handling in tiny RCU.

rcu: Provide RCU CPU stall warnings for tiny RCU

2013-01-29T06:06:21Z

Tiny RCU has historically omitted RCU CPU stall warnings in order to reduce memory requirements, however, lack of these warnings caused Thomas Gleixner some debugging pain recently. Therefore, this commit adds RCU CPU stall warnings to tiny RCU if RCU_TRACE=y. This keeps the memory footprint small, while still enabling CPU stall warnings in kernels built to enable them. Updated to include Josh Triplett's suggested use of RCU_STALL_COMMON config variable to simplify #if expressions. Reported-by: Thomas Gleixner Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett

rcu: Reduce rcutorture tracing

2013-01-08T22:14:55Z

Currently, rcutorture traces every read-side access. This can be problematic because even a two-minute rcutorture run on a two-CPU system can generate 28,853,363 reads. Normally, only a failing read is of interest, so this commit traces adjusts rcutorture's tracing to only trace failing reads. The resulting event tracing records the time and the ->completed value captured at the beginning of the RCU read-side critical section, allowing correlation with other event-tracing messages. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett [ paulmck: Add fix to build problem located by Randy Dunlap based on diagnosis by Steven Rostedt. ]