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f96e8577da
Here we introduce a test module for introducing a long preempt or irq disable delay in the kernel which the preemptoff or irqsoff tracers can detect. This module is to be used only for test purposes and is default disabled. Following is the expected output (only briefly shown) that can be parsed to verify that the tracers are working correctly. We will use this from the kselftests in future patches. For the preemptoff tracer: echo preemptoff > /d/tracing/current_tracer sleep 1 insmod ./preemptirq_delay_test.ko test_mode=preempt delay=500000 sleep 1 bash-4.3# cat /d/tracing/trace preempt -1066 2...2 0us@: preemptirq_delay_run <-preemptirq_delay_run preempt -1066 2...2 500002us : preemptirq_delay_run <-preemptirq_delay_run preempt -1066 2...2 500004us : tracer_preempt_on <-preemptirq_delay_run preempt -1066 2...2 500012us : <stack trace> => kthread => ret_from_fork For the irqsoff tracer: echo irqsoff > /d/tracing/current_tracer sleep 1 insmod ./preemptirq_delay_test.ko test_mode=irq delay=500000 sleep 1 bash-4.3# cat /d/tracing/trace irq dis -1069 1d..1 0us@: preemptirq_delay_run irq dis -1069 1d..1 500001us : preemptirq_delay_run irq dis -1069 1d..1 500002us : tracer_hardirqs_on <-preemptirq_delay_run irq dis -1069 1d..1 500005us : <stack trace> => ret_from_fork Link: http://lkml.kernel.org/r/20180712213611.GA8743@joelaf.mtv.corp.google.com Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Julia Cartwright <julia@ni.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Glexiner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@google.com> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> [ Erick is a co-developer of this commit ] Signed-off-by: Erick Reyes <erickreyes@google.com> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
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| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.