A sample application to demonstrate use of kernel event logger feature. #4552

SavinayDharmappa · 2017-10-25T13:00:59Z

dbkinder

suggested edits

dbkinder · 2017-10-25T23:41:20Z

samples/subsys/logging/kernel_event_logger/README.rst

@@ -0,0 +1,40 @@
+.. _kerneleventlogger_sample:
+
+Kerneleventlogger Sample


How about:

Kernel Event Logger Sample ##########################

Note the #### underline must be at least as long as the title above it.

dbkinder · 2017-10-25T23:44:13Z

samples/subsys/logging/kernel_event_logger/README.rst

+
+A simple application that demonstrates use of kernel event
+logger feature.Two threads (A and B) of same priority are
+created and another thread with less priority (i.e event_


Words that end with an underscore are meaningful to the doc gen process, so break the line before event_ so the line doesn't end with an underscore. Also some clarity edits:

created and a third thread with lower priority (i.e., event_logger_thread) is also created, which reads the events from

dbkinder · 2017-10-25T23:45:45Z

samples/subsys/logging/kernel_event_logger/README.rst

+********
+
+A simple application that demonstrates use of kernel event
+logger feature.Two threads (A and B) of same priority are


add a space after the period ending a sentence

dbkinder · 2017-10-25T23:46:31Z

samples/subsys/logging/kernel_event_logger/README.rst

+********
+
+A simple application that demonstrates use of kernel event
+logger feature.Two threads (A and B) of same priority are


and change to "of the same priority"

dbkinder · 2017-10-25T23:49:31Z

samples/subsys/logging/kernel_event_logger/README.rst

+logger feature.Two threads (A and B) of same priority are
+created and another thread with less priority (i.e event_
+logger_thread)is also created which reads the events from
+kernel event loggerbuffer and prints on to the console.


Change to:

kernel event logger's buffer

to match what you've written below, and change "prints on to" to just "prints to"

dbkinder · 2017-10-25T23:50:00Z

samples/subsys/logging/kernel_event_logger/README.rst

+created and another thread with less priority (i.e event_
+logger_thread)is also created which reads the events from
+kernel event loggerbuffer and prints on to the console.
+When thread 'A' gets schecduled it will sleep for 1 second.


dbkinder · 2017-10-25T23:50:44Z

samples/subsys/logging/kernel_event_logger/README.rst

+kernel event loggerbuffer and prints on to the console.
+When thread 'A' gets schecduled it will sleep for 1 second.
+Similarly when thread 'B' gets scheduled it will sleep for
+0.5 seconds. When both A and B are sleeping event logger


change to:

... are sleeping, the event logger

dbkinder · 2017-10-25T23:51:19Z

samples/subsys/logging/kernel_event_logger/README.rst

+When thread 'A' gets schecduled it will sleep for 1 second.
+Similarly when thread 'B' gets scheduled it will sleep for
+0.5 seconds. When both A and B are sleeping event logger
+thread gets scheduled and retrieve the events captured


dbkinder · 2017-10-25T23:51:36Z

samples/subsys/logging/kernel_event_logger/README.rst

+Similarly when thread 'B' gets scheduled it will sleep for
+0.5 seconds. When both A and B are sleeping event logger
+thread gets scheduled and retrieve the events captured
+from kernel event loggers buffer and prints it on the console.


dbkinder · 2017-10-25T23:59:55Z

samples/subsys/logging/kernel_event_logger/README.rst

@@ -0,0 +1,40 @@
+.. _kerneleventlogger_sample:


This is the first document in the logging area, so you'll need to also add a file samples/subsys/logging/logging.rst that looks like samples/subsys/console/console.rst (copy that one and edit the title). This will remove the "not included in a toc-tree" warning.

nashif · 2017-10-26T08:26:24Z

samples/subsys/logging/kernel_event_logger/src/Makefile

+obj-y += main.o
+
+ccflags-y += -I${ZEPHYR_BASE}/ext/debug/segger/rtt
+ccflags-y += -I${ZEPHYR_BASE}/ext/debug/segger/systemview


you do not need those

nashif · 2017-10-26T08:27:02Z

samples/subsys/logging/kernel_event_logger/src/main.c

+
+		timestamp = event_data[0];
+
+		switch (event_id) {


add a default to the switch

nashif · 2017-10-26T08:27:34Z

samples/subsys/logging/kernel_event_logger/src/main.c

+		case KERNEL_EVENT_LOGGER_SLEEP_EVENT_ID:
+			break;
+		case KERNEL_EVENT_LOGGER_THREAD_EVENT_ID:
+			printk("thread = %x, is moved to = %s ,


reformat this message, this should fit in 2 lines and would be more readable.

nashif · 2017-10-26T08:28:20Z

samples/subsys/logging/kernel_event_logger/src/main.c

+static u32_t timestamp;
+char thread_event_type[][12] = {"REDAY_Q", "PEND_STATE", "EXIT_STATE"};
+
+static void event_logger_thread(void)


why not make this the main thread?

The thread which reads event from the kernel event logger should be of least priority, because this thread should not affect application related threads. As main thread is set with priority zero, it should not be used for reading events from event loggers

you can change the main thread priority using CONFIG_MAIN_THREAD_PRIORITY

for example: https://gist.github.com/nashif/372f216ca8fe84c560489c9171a9c219

dbkinder

almost done...

dbkinder · 2017-10-30T20:47:07Z

samples/subsys/logging/kernel_event_logger/README.rst

+
+A simple application that demonstrates use of kernel event
+logger feature. Two threads (A and B) of the same priority
+are created and main thread is configured to have low priority ,


delete space before the comma

dbkinder · 2017-10-30T20:48:17Z

samples/subsys/logging/kernel_event_logger/README.rst

+which reads the events from kernel event logger's buffer and
+prints to the console. When thread 'A' gets scheduled it will
+sleep for 1 second. Similarly when thread 'B' gets scheduled
+it will sleep for 0.5 seconds. When both A and B are sleeping ,


delete space before the comma

A CPU fault occurs when sys_k_event_logger_get_wait() api invoked with config KERNEL_EVENT_LOGGER_THREAD enabled. sys_k_event_logger_get_wait() supposed to pend on a semaphore when all the events from kernel event logger are read.But when sys_k_event_logger_get_wait() inovked with config KERNEL_EVENT_LOGGER_THREAD(i.e captures thread events) subsquent call inside this function will write to kernel event log buffer to capture pend event.This will release the semaphore on which sys_k_event_logger_get_wait() was pending hence thread gets unpend before swap gets called. Which in other words a thread which is invoking sys_k_event_logger_get_wait()(i. e sem_count = 0) get pends and unpends in single function flow when KERNEL_EVENT_LOGGER_THREAD enabled. This would cause overlapping of the stack address where return address of "_pend_current_thread" stored with esp of callee saved(i. e thread->callee_saved.esp). Thus return adrress of "_pend_current_thread" would be overwitten with zero. Which in turn causes CPU fault. The thread invoking sys_k_event_logger_get_wait() supposed to only read the events of the threads which logged to kernel event logger buffer. But it should not write to kernel event logger buffer. Otherwise it would cause the race condition explained above. Signed-off-by: Savinay Dharmappa <[email protected]>

patch adds a sample application to demonstrate use of kernel event logger feature. Signed-off-by: Savinay Dharmappa <[email protected]>

SavinayDharmappa requested a review from dbkinder as a code owner October 25, 2017 13:01

dbkinder suggested changes Oct 26, 2017

View reviewed changes

nashif requested changes Oct 26, 2017

View reviewed changes

SavinayDharmappa force-pushed the issue_3412 branch 5 times, most recently from db20ecf to f8e847a Compare October 30, 2017 16:04

dbkinder suggested changes Oct 30, 2017

View reviewed changes

SavinayDharmappa force-pushed the issue_3412 branch from f8e847a to 8a8bd0d Compare October 31, 2017 06:13

SavinayDharmappa added 2 commits October 31, 2017 19:24

sample: subsys: logging: kernel_event_logger: Add sample application

8a8bd0d

patch adds a sample application to demonstrate use of kernel event logger feature. Signed-off-by: Savinay Dharmappa <[email protected]>

nashif approved these changes Nov 3, 2017

View reviewed changes

nashif merged commit 4cec152 into zephyrproject-rtos:master Nov 3, 2017

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

A sample application to demonstrate use of kernel event logger feature. #4552

A sample application to demonstrate use of kernel event logger feature. #4552

SavinayDharmappa commented Oct 25, 2017 •

edited by nashif

Loading

dbkinder left a comment

dbkinder Oct 25, 2017

SavinayDharmappa Oct 27, 2017

dbkinder Oct 25, 2017

dbkinder Oct 25, 2017

SavinayDharmappa Oct 27, 2017

dbkinder Oct 25, 2017

SavinayDharmappa Oct 27, 2017

dbkinder Oct 25, 2017

dbkinder Oct 25, 2017

dbkinder Oct 25, 2017

dbkinder Oct 25, 2017

dbkinder Oct 25, 2017

dbkinder Oct 25, 2017

SavinayDharmappa Oct 27, 2017

nashif Oct 26, 2017

nashif Oct 26, 2017

SavinayDharmappa Oct 27, 2017

nashif Oct 26, 2017

SavinayDharmappa Oct 27, 2017

nashif Oct 26, 2017

SavinayDharmappa Oct 27, 2017

nashif Oct 27, 2017

nashif Oct 27, 2017

SavinayDharmappa Oct 30, 2017

dbkinder left a comment

dbkinder Oct 30, 2017

SavinayDharmappa Oct 31, 2017

dbkinder Oct 30, 2017

SavinayDharmappa Oct 31, 2017

		@@ -0,0 +1,40 @@
		.. _kerneleventlogger_sample:

		Kerneleventlogger Sample

A sample application to demonstrate use of kernel event logger feature. #4552

A sample application to demonstrate use of kernel event logger feature. #4552

Conversation

SavinayDharmappa commented Oct 25, 2017 • edited by nashif Loading

dbkinder left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

dbkinder left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

SavinayDharmappa commented Oct 25, 2017 •

edited by nashif

Loading