kernel.git/include/trace/events/rcu.h, branch linux-6.2.y

rcu: Fix rcu_torture_read ftrace event

2023-04-06T10:12:45Z

commit d18a04157fc171fd48075e3dc96471bd3b87f0dd upstream. Fix the rcutorturename field so that its size is correctly reported in the text format embedded in trace.dat files. As it stands, it is reported as being of size 1: field:char rcutorturename[8]; offset:8; size:1; signed:0; Signed-off-by: Douglas Raillard Reviewed-by: Mukesh Ojha Cc: stable@vger.kernel.org Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()") Reviewed-by: Steven Rostedt (Google) [ boqun: Add "Cc" and "Fixes" tags per Steven ] Signed-off-by: Boqun Feng Signed-off-by: Paul E. McKenney Signed-off-by: Greg Kroah-Hartman

rcu: Refactor rcu_barrier() empty-list handling

2022-02-08T18:12:28Z

This commit saves a few lines by checking first for an empty callback list. If the callback list is empty, then that CPU is taken care of, regardless of its online or nocb state. Also simplify tracing accordingly and fold a few lines together. Signed-off-by: Paul E. McKenney

rcu/nocb: Unify timers

2021-05-12T19:10:23Z

Now that ->nocb_timer and ->nocb_bypass_timer have become quite similar, this commit merges them together. A new RCU_NOCB_WAKE_BYPASS wake level is introduced. As a result, timers perform all kinds of deferred wake ups but other deferred wakeup callsites only handle non-bypass wakeups in order not to wake up rcuo too early. The timer also unconditionally executes a full barrier so as to order timer_pending() and callback enqueue although the path performing RCU_NOCB_WAKE_FORCE that makes use of it is debatable. It should also test against the rdp leader instead of the current rdp. This unconditional full barrier shouldn't bring visible overhead since these timers almost never fire. Signed-off-by: Frederic Weisbecker Cc: Josh Triplett Cc: Lai Jiangshan Cc: Joel Fernandes Cc: Neeraj Upadhyay Cc: Boqun Feng Signed-off-by: Paul E. McKenney

Merge tag 'trace-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2021-05-03T18:19:54Z

Pull tracing updates from Steven Rostedt: "New feature: - A new "func-no-repeats" option in tracefs/options directory. When set the function tracer will detect if the current function being traced is the same as the previous one, and instead of recording it, it will keep track of the number of times that the function is repeated in a row. And when another function is recorded, it will write a new event that shows the function that repeated, the number of times it repeated and the time stamp of when the last repeated function occurred. Enhancements: - In order to implement the above "func-no-repeats" option, the ring buffer timestamp can now give the accurate timestamp of the event as it is being recorded, instead of having to record an absolute timestamp for all events. This helps the histogram code which no longer needs to waste ring buffer space. - New validation logic to make sure all trace events that access dereferenced pointers do so in a safe way, and will warn otherwise. Fixes: - No longer limit the PIDs of tasks that are recorded for "saved_cmdlines" to PID_MAX_DEFAULT (32768), as systemd now allows for a much larger range. This caused the mapping of PIDs to the task names to be dropped for all tasks with a PID greater than 32768. - Change trace_clock_global() to never block. This caused a deadlock. Clean ups: - Typos, prototype fixes, and removing of duplicate or unused code. - Better management of ftrace_page allocations" * tag 'trace-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (32 commits) tracing: Restructure trace_clock_global() to never block tracing: Map all PIDs to command lines ftrace: Reuse the output of the function tracer for func_repeats tracing: Add "func_no_repeats" option for function tracing tracing: Unify the logic for function tracing options tracing: Add method for recording "func_repeats" events tracing: Add "last_func_repeats" to struct trace_array tracing: Define new ftrace event "func_repeats" tracing: Define static void trace_print_time() ftrace: Simplify the calculation of page number for ftrace_page->records some more ftrace: Store the order of pages allocated in ftrace_page tracing: Remove unused argument from "ring_buffer_time_stamp() tracing: Remove duplicate struct declaration in trace_events.h tracing: Update create_system_filter() kernel-doc comment tracing: A minor cleanup for create_system_filter() kernel: trace: Mundane typo fixes in the file trace_events_filter.c tracing: Fix various typos in comments scripts/recordmcount.pl: Make vim and emacs indent the same scripts/recordmcount.pl: Make indent spacing consistent tracing: Add a verifier to check string pointers for trace events ...

tracing: Fix various typos in comments

2021-03-23T18:08:18Z

Fix ~59 single-word typos in the tracing code comments, and fix the grammar in a handful of places. Link: https://lore.kernel.org/r/20210322224546.GA1981273@gmail.com Link: https://lkml.kernel.org/r/20210323174935.GA4176821@gmail.com Reviewed-by: Randy Dunlap Signed-off-by: Ingo Molnar Signed-off-by: Steven Rostedt (VMware)

rcu/tree: Add a trace event for RCU CPU stall warnings

2021-03-15T20:53:24Z

This commit adds a trace event which allows tracing the beginnings of RCU CPU stall warnings on systems where sysctl_panic_on_rcu_stall is disabled. The first parameter is the name of RCU flavor like other trace events. The second parameter indicates whether this is a stall of an expedited grace period, a self-detected stall of a normal grace period, or a stall of a normal grace period detected by some CPU other than the one that is stalled. RCU CPU stall warnings are often caused by external-to-RCU issues, for example, in interrupt handling or task scheduling. Therefore, this event uses TRACE_EVENT, not TRACE_EVENT_RCU, to avoid requiring those interested in tracing RCU CPU stalls to rebuild their kernels with CONFIG_RCU_TRACE=y. Reviewed-by: Uladzislau Rezki (Sony) Reviewed-by: Neeraj Upadhyay Signed-off-by: Sangmoon Kim Signed-off-by: Paul E. McKenney

rcu/trace: Add tracing for how segcb list changes

2021-01-07T00:24:19Z

This commit adds tracing to track how the segcb list changes before/after acceleration, during queuing and during dequeuing. This tracing helped discover an optimization that avoided needless GP requests when no callbacks were accelerated. The tracing overhead is minimal as each segment's length is now stored in the respective segment. Reviewed-by: Frederic Weisbecker Reviewed-by: Neeraj Upadhyay Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney

rcu/trace: Print negative GP numbers correctly

2020-08-25T01:36:04Z

GP numbers start from -300 and gp_seq numbers start of -1200 (for a shift of 2). These negative numbers are printed as unsigned long which not only takes up more text space, but is rather confusing to the reader as they have to constantly expend energy to truncate the number. Just print the negative numbering directly. Cc: Uladzislau Rezki (Sony) Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney

Merge branches 'doc.2020.06.29a', 'fixes.2020.06.29a', 'kfree_rcu.2020.06.29a', 'rcu-tasks.2020.06.29a', 'scale.2020.06.29a', 'srcu.2020.06.29a' and 'torture.2020.06.29a' into HEAD

2020-06-29T19:03:15Z

doc.2020.06.29a: Documentation updates. fixes.2020.06.29a: Miscellaneous fixes. kfree_rcu.2020.06.29a: kfree_rcu() updates. rcu-tasks.2020.06.29a: RCU Tasks updates. scale.2020.06.29a: Read-side scalability tests. srcu.2020.06.29a: SRCU updates. torture.2020.06.29a: Torture-test updates.

rcu: Rename _kfree_callback/_kfree_rcu_offset/kfree_call_*

2020-06-29T18:59:25Z

The following changes are introduced: 1. Rename rcu_invoke_kfree_callback() to rcu_invoke_kvfree_callback(), as well as the associated trace events, so the rcu_kfree_callback(), becomes rcu_kvfree_callback(). The reason is to be aligned with kvfree() notation. 2. Rename __is_kfree_rcu_offset to __is_kvfree_rcu_offset. All RCU paths use kvfree() now instead of kfree(), thus rename it. 3. Rename kfree_call_rcu() to the kvfree_call_rcu(). The reason is, it is capable of freeing vmalloc() memory now. Do the same with __kfree_rcu() macro, it becomes __kvfree_rcu(), the goal is the same. Reviewed-by: Joel Fernandes (Google) Co-developed-by: Joel Fernandes (Google) Signed-off-by: Joel Fernandes (Google) Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Paul E. McKenney