Merge tag 'trace-tools-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull rtla trace tooling updates from Steven Rostedt:

 - Officially add Tomas Glozar as a maintainer to RTLA tool

 - Add for_each_monitored_cpu() helper

   In multiple places, RTLA tools iterate over the list of CPUs running
   tracer threads.

   Use single helper instead of repeating the for/if combination.

 - Remove unused variable option_index in argument parsing

   RTLA tools use getopt_long() for argument parsing. For its last
   argument, an unused variable "option_index" is passed.

   Remove the variable and pass NULL to getopt_long() to shorten the
   naturally long parsing functions, and make them more readable.

 - Fix unassigned nr_cpus after code consolidation

   In recent code consolidation, timerlat tool cleanup, previously
   implemented separately for each tool, was moved to a common function
   timerlat_free().

   The cleanup relies on nr_cpus being set. This was not done in the new
   function, leaving the variable uninitialized.

   Initialize the variable properly, and remove silencing of compiler
   warning for uninitialized variables.

 - Stop tracing on user latency in BPF mode

   Despite the name, rtla-timerlat's -T/--thread option sets timerlat's
   stop_tracing_total_us option, which also stops tracing on
   return-from-user latency, not only on thread latency.

   Implement the same behavior also in BPF sample collection stop
   tracing handler to avoid a discrepancy and restore correspondence of
   behavior with the equivalent option of cyclictest.

 - Fix threshold actions always triggering

   A bug in threshold action logic caused the action to execute even if
   tracing did not stop because of threshold.

   Fix the logic to stop correctly.

 - Fix few minor issues in tests

   Extend tests that were shown to need it to 5s, fix osnoise test
   calling timerlat by mistake, and use new, more reliable output
   checking in timerlat's "top stop at failed action" test.

 - Do not print usage on argument parsing error

   RTLA prints the entire usage message on encountering errors in
   argument parsing, like a malformed CPU list.

   The usage message has gotten too long. Instead of printing it, use
   newly added fatal() helper function to simply exit with the error
   message, excluding the usage.

 - Fix unintuitive -C/--cgroup interface

   "-C cgroup" and "--cgroup cgroup" are invalid syntax, despite that
   being a common way to specify an option with argument. Moreover,
   using them fails silently and no cgroup is set.

   Create new helper function to unify the handling of all such options
   and allow all of:

     -Xsomething
     -X=something
     -X something

   as well as the equivalent for the long option.

 - Fix -a overriding -t argument filename

   Fix a bug where -a following -t custom_file.txt overrides the custom
   filename with the default timerlat_trace.txt.

 - Stop tracing correctly on multiple events at once

   In some race scenarios, RTLA BPF sample collection might send
   multiple stop tracing events via the BPF ringbuffer at once.

   Compare the number of events for != 0 instead of == 1 to cover for
   this scenario and stop tracing properly.

* tag 'trace-tools-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  rtla/timerlat: Exit top main loop on any non-zero wait_retval
  rtla/tests: Don't rely on matching ^1ALL
  rtla: Fix -a overriding -t argument
  rtla: Fix -C/--cgroup interface
  tools/rtla: Replace osnoise_hist_usage("...") with fatal("...")
  tools/rtla: Replace osnoise_top_usage("...") with fatal("...")
  tools/rtla: Replace timerlat_hist_usage("...") with fatal("...")
  tools/rtla: Replace timerlat_top_usage("...") with fatal("...")
  tools/rtla: Add fatal() and replace error handling pattern
  rtla/tests: Fix osnoise test calling timerlat
  rtla/tests: Extend action tests to 5s
  tools/rtla: Fix --on-threshold always triggering
  rtla/timerlat_bpf: Stop tracing on user latency
  tools/rtla: Fix unassigned nr_cpus
  tools/rtla: Remove unused optional option_index
  tools/rtla: Add for_each_monitored_cpu() helper
  MAINTAINERS: Add Tomas Glozar as a maintainer to RTLA tool

Author: torvalds

Documentation/tools/rtla/common_options.txt

@@ -48,7 +48,7 @@
 
         If not set, tracer threads keep their default priority. For rtla user threads, it is set to SCHED_FIFO with priority 95. For kernel threads, see *osnoise* and *timerlat* tracer documentation for the running kernel version.
 
-**-C**, **--cgroup**\[*=cgroup*]
+**-C**, **--cgroup** \[*cgroup*]
 
         Set a *cgroup* to the tracer's threads. If the **-C** option is passed without arguments, the tracer's thread will inherit **rtla**'s *cgroup*. Otherwise, the threads will be placed on the *cgroup* passed to the option.
 

MAINTAINERS

@@ -21802,8 +21802,12 @@ F:	tools/testing/selftests/rtc/
 
 Real-time Linux Analysis (RTLA) tools
 M:	Steven Rostedt <rostedt@goodmis.org>
+M:	Tomas Glozar <tglozar@redhat.com>
 L:	linux-trace-kernel@vger.kernel.org
+L:	linux-kernel@vger.kernel.org
 S:	Maintained
+Q:	https://patchwork.kernel.org/project/linux-trace-kernel/list/
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
 F:	Documentation/tools/rtla/
 F:	tools/tracing/rtla/
 

tools/tracing/rtla/Makefile.rtla

@@ -18,7 +18,7 @@ export CC AR STRIP PKG_CONFIG LD_SO_CONF_PATH LDCONFIG
 FOPTS		:= -flto=auto -ffat-lto-objects -fexceptions -fstack-protector-strong	\
 		-fasynchronous-unwind-tables -fstack-clash-protection
 WOPTS		:= -O -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2		\
-		-Wp,-D_GLIBCXX_ASSERTIONS -Wno-maybe-uninitialized
+		-Wp,-D_GLIBCXX_ASSERTIONS
 
 ifeq ($(CC),clang)
   FOPTS		:= $(filter-out -flto=auto -ffat-lto-objects, $(FOPTS))

tools/tracing/rtla/src/common.c

@@ -268,6 +268,10 @@ int top_main_loop(struct osnoise_tool *tool)
 			tool->ops->print_stats(tool);
 
 		if (osnoise_trace_is_off(tool, record)) {
+			if (stop_tracing)
+				/* stop tracing requested, do not perform actions */
+				return 0;
+
 			actions_perform(&params->threshold_actions);
 
 			if (!params->threshold_actions.continue_flag)
@@ -315,20 +319,22 @@ int hist_main_loop(struct osnoise_tool *tool)
 		}
 
 		if (osnoise_trace_is_off(tool, tool->record)) {
+			if (stop_tracing)
+				/* stop tracing requested, do not perform actions */
+				break;
+
 			actions_perform(&params->threshold_actions);
 
-			if (!params->threshold_actions.continue_flag) {
+			if (!params->threshold_actions.continue_flag)
 				/* continue flag not set, break */
 				break;
 
-				/* continue action reached, re-enable tracing */
-				if (tool->record)
-					trace_instance_start(&tool->record->trace);
-				if (tool->aa)
-					trace_instance_start(&tool->aa->trace);
-				trace_instance_start(&tool->trace);
-			}
-			break;
+			/* continue action reached, re-enable tracing */
+			if (tool->record)
+				trace_instance_start(&tool->record->trace);
+			if (tool->aa)
+				trace_instance_start(&tool->aa->trace);
+			trace_instance_start(&tool->trace);
 		}
 
 		/* is there still any user-threads ? */

tools/tracing/rtla/src/common.h

@@ -107,6 +107,10 @@ struct common_params {
 	struct timerlat_u_params user;
 };
 
+#define for_each_monitored_cpu(cpu, nr_cpus, common) \
+	for (cpu = 0; cpu < nr_cpus; cpu++) \
+		if (!(common)->cpus || CPU_ISSET(cpu, &(common)->monitored_cpus))
+
 struct tool_ops;
 
 /*