Commit Graph

330 Commits

Author SHA1 Message Date
Mike Leach
82e0c782f8 docs: coresight: Update documentation for CoreSight to cover CTI
Add new document covering CTI / CTM usage in CoreSight.

Add section in coresight.rst introducing CTI and CTM modules with link
to new document.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-11-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21 11:32:21 +01:00
Linus Torvalds
41dcd67e88 A handful of small documentation fixes that wandered in.
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Merge tag 'docs-5.6-2' of git://git.lwn.net/linux

Pull Documentation fixes from Jonathan Corbet:
 "A handful of small documentation fixes that wandered in"

* tag 'docs-5.6-2' of git://git.lwn.net/linux:
  Allow git builds of Sphinx
  Documentation: changes.rst: update several outdated project URLs
  Documentation: build warnings related to missing blank lines after explicit markups has been fixed
  mailmap: add entry for Tiezhu Yang
  Documentation/ko_KR/howto: Update a broken link
  Documentation/ko_KR/howto: Update broken web addresses
  docs/locking: Fix outdated section names
2020-02-07 13:03:10 -08:00
Linus Torvalds
e310396bb8 Tracing updates:
- Added new "bootconfig".
    Looks for a file appended to initrd to add boot config options.
    This has been discussed thoroughly at Linux Plumbers.
    Very useful for adding kprobes at bootup.
    Only enabled if "bootconfig" is on the real kernel command line.
 
  - Created dynamic event creation.
    Merges common code between creating synthetic events and
      kprobe events.
 
  - Rename perf "ring_buffer" structure to "perf_buffer"
 
  - Rename ftrace "ring_buffer" structure to "trace_buffer"
    Had to rename existing "trace_buffer" to "array_buffer"
 
  - Allow trace_printk() to work withing (some) tracing code.
 
  - Sort of tracing configs to be a little better organized
 
  - Fixed bug where ftrace_graph hash was not being protected properly
 
  - Various other small fixes and clean ups
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Merge tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Added new "bootconfig".

   This looks for a file appended to initrd to add boot config options,
   and has been discussed thoroughly at Linux Plumbers.

   Very useful for adding kprobes at bootup.

   Only enabled if "bootconfig" is on the real kernel command line.

 - Created dynamic event creation.

   Merges common code between creating synthetic events and kprobe
   events.

 - Rename perf "ring_buffer" structure to "perf_buffer"

 - Rename ftrace "ring_buffer" structure to "trace_buffer"

   Had to rename existing "trace_buffer" to "array_buffer"

 - Allow trace_printk() to work withing (some) tracing code.

 - Sort of tracing configs to be a little better organized

 - Fixed bug where ftrace_graph hash was not being protected properly

 - Various other small fixes and clean ups

* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
  bootconfig: Show the number of nodes on boot message
  tools/bootconfig: Show the number of bootconfig nodes
  bootconfig: Add more parse error messages
  bootconfig: Use bootconfig instead of boot config
  ftrace: Protect ftrace_graph_hash with ftrace_sync
  ftrace: Add comment to why rcu_dereference_sched() is open coded
  tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
  tracing: Annotate ftrace_graph_hash pointer with __rcu
  bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
  tracing: Use seq_buf for building dynevent_cmd string
  tracing: Remove useless code in dynevent_arg_pair_add()
  tracing: Remove check_arg() callbacks from dynevent args
  tracing: Consolidate some synth_event_trace code
  tracing: Fix now invalid var_ref_vals assumption in trace action
  tracing: Change trace_boot to use synth_event interface
  tracing: Move tracing selftests to bottom of menu
  tracing: Move mmio tracer config up with the other tracers
  tracing: Move tracing test module configs together
  tracing: Move all function tracing configs together
  tracing: Documentation for in-kernel synthetic event API
  ...
2020-02-06 07:12:11 +00:00
Sameer Rahmani
ff1e81a7e2 Documentation: build warnings related to missing blank lines after explicit markups has been fixed
Fix for several documentation build warnings related to missing blank lines
after explicit mark up.

Exact warning message:
 WARNING: Explicit markup ends without a blank line; unexpected unindent.

Signed-off-by: Sameer Rahmani <lxsameer@gnu.org>
Link: https://lore.kernel.org/r/20200203201543.24834-1-lxsameer@gnu.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-05 10:30:03 -07:00
Tom Zanussi
34ed63573b tracing: Documentation for in-kernel synthetic event API
Add Documentation for creating and generating synthetic events from
modules.

Link: http://lkml.kernel.org/r/734bf8789ff8700000c9acde61a553427910ddb5.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:29 -05:00
Mauro Carvalho Chehab
d0ce47cb99 docs: tracing: Fix a broken label
Sphinx warnings about his:

	Documentation/trace/kprobetrace.rst:68: WARNING: undefined label: user_mem_access (if the link has no caption the label must precede a section header)

The problem is quite simple: Sphinx wants a blank line after
references.

Link: http://lkml.kernel.org/r/a83ea390bc28784518fce772b4c961ea1c976f14.1560883872.git.mchehab+samsung@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-28 23:14:13 -05:00
Masami Hiramatsu
b8381ce7aa Documentation: tracing: Fix typos in boot-time tracing documentation
Fix typos in boottime-trace.rst according to Randy's suggestions.

Link: http://lkml.kernel.org/r/157949060335.25888.13153184562531693684.stgit@devnote2

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 18:25:16 -05:00
Masami Hiramatsu
4778194794 Documentation: tracing: Add boot-time tracing document
Add a documentation about boot-time tracing options in
boot config.

Link: http://lkml.kernel.org/r/157867246028.17873.8047384554383977870.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:42 -05:00
Frank A. Cancio Bello
1209f45f7d docs: ftrace: Fix small notation mistake
The use of iff ("if and only if") notation is not accurate in this case.

Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Frank A. Cancio Bello <frank@generalsoftwareinc.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/22f9a98a972c3155c7b478247a087a5efafde774.1577231751.git.frank@generalsoftwareinc.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-10 10:52:47 -07:00
Frank A. Cancio Bello
5b8914a67e docs: ftrace: Fix typos
Fix minor typos in the doc.

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Frank A. Cancio Bello <frank@generalsoftwareinc.com>
Link: https://lore.kernel.org/r/9ef705d0208a4ca0852fed69bc0838a589a4df85.1577231751.git.frank@generalsoftwareinc.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-10 10:52:28 -07:00
Frank A. Cancio Bello
a65d634e63 docs: ftrace: Clarify the RAM impact of buffer_size_kb
The current text could mislead the user into believing that the number
of pages allocated by each CPU ring buffer is calculated by the round
up of the division: buffer_size_kb / PAGE_SIZE.

Clarifies that a few extra pages may be allocated to accommodate buffer
management meta-data.

Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Suggested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Frank A. Cancio Bello <frank@generalsoftwareinc.com>
Link: https://lore.kernel.org/r/6f33be5f3d60e5ffc061d8d2b329d3d3ccf22a8c.1577231751.git.frank@generalsoftwareinc.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-01-10 10:51:34 -07:00
Frank A. Cancio Bello
d693b2883c docs: ftrace: Specifies when buffers get clear
Clarify a few places where the ring buffer and the "snapshot" buffer
are cleared as a side effect of an operation.

This will avoid users lost of tracing data because of these so far
undocumented behavior.

Signed-off-by: Frank A. Cancio Bello <frank@generalsoftwareinc.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20191218191553.q4lwyxmquvtjzjfz@frank-laptop
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-12-19 09:18:33 -07:00
Linus Torvalds
937d6eefc7 Here's the main documentation changes for 5.5:
- Various kerneldoc script enhancements.
 
  - More RST conversions; those are slowing down as we run out of things to
    convert, but we're a ways from done still.
 
  - Dan's "maintainer profile entry" work landed at last.  Now we just need
    to get maintainers to fill in the profiles...
 
  - A reworking of the parallel build setup to work better with a variety of
    systems (and to not take over huge systems entirely in particular).
 
  - The MAINTAINERS file is now converted to RST during the build.
    Hopefully nobody ever tries to print this thing, or they will need to
    load a lot of paper.
 
  - A script and documentation making it easy for maintainers to add Link:
    tags at commit time.
 
 Also included is the removal of a bunch of spurious CR characters.
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Merge tag 'docs-5.5a' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "Here are the main documentation changes for 5.5:

   - Various kerneldoc script enhancements.

   - More RST conversions; those are slowing down as we run out of
     things to convert, but we're a ways from done still.

   - Dan's "maintainer profile entry" work landed at last. Now we just
     need to get maintainers to fill in the profiles...

   - A reworking of the parallel build setup to work better with a
     variety of systems (and to not take over huge systems entirely in
     particular).

   - The MAINTAINERS file is now converted to RST during the build.
     Hopefully nobody ever tries to print this thing, or they will need
     to load a lot of paper.

   - A script and documentation making it easy for maintainers to add
     Link: tags at commit time.

  Also included is the removal of a bunch of spurious CR characters"

* tag 'docs-5.5a' of git://git.lwn.net/linux: (91 commits)
  docs: remove a bunch of stray CRs
  docs: fix up the maintainer profile document
  libnvdimm, MAINTAINERS: Maintainer Entry Profile
  Maintainer Handbook: Maintainer Entry Profile
  MAINTAINERS: Reclaim the P: tag for Maintainer Entry Profile
  docs, parallelism: Rearrange how jobserver reservations are made
  docs, parallelism: Do not leak blocking mode to other readers
  docs, parallelism: Fix failure path and add comment
  Documentation: Remove bootmem_debug from kernel-parameters.txt
  Documentation: security: core.rst: fix warnings
  Documentation/process/howto/kokr: Update for 4.x -> 5.x versioning
  Documentation/translation: Use Korean for Korean translation title
  docs/memory-barriers.txt: Remove remaining references to mmiowb()
  docs/memory-barriers.txt/kokr: Update I/O section to be clearer about CPU vs thread
  docs/memory-barriers.txt/kokr: Fix style, spacing and grammar in I/O section
  Documentation/kokr: Kill all references to mmiowb()
  docs/memory-barriers.txt/kokr: Rewrite "KERNEL I/O BARRIER EFFECTS" section
  docs: Add initial documentation for devfreq
  Documentation: Document how to get links with git am
  docs: Add request_irq() documentation
  ...
2019-12-02 11:51:02 -08:00
Linus Torvalds
95f1fa9e34 New tracing features:
- PERAMAENT flag to ftrace_ops when attaching a callback to a function
    As /proc/sys/kernel/ftrace_enabled when set to zero will disable all
    attached callbacks in ftrace, this has a detrimental impact on live
    kernel tracing, as it disables all that it patched. If a ftrace_ops
    is registered to ftrace with the PERMANENT flag set, it will prevent
    ftrace_enabled from being disabled, and if ftrace_enabled is already
    disabled, it will prevent a ftrace_ops with PREMANENT flag set from
    being registered.
 
  - New register_ftrace_direct(). As eBPF would like to register its own
    trampolines to be called by the ftrace nop locations directly,
    without going through the ftrace trampoline, this function has been
    added. This allows for eBPF trampolines to live along side of
    ftrace, perf, kprobe and live patching. It also utilizes the ftrace
    enabled_functions file that keeps track of functions that have been
    modified in the kernel, to allow for security auditing.
 
  - Allow for kernel internal use of ftrace instances. Subsystems in
    the kernel can now create and destroy their own tracing instances
    which allows them to have their own tracing buffer, and be able
    to record events without worrying about other users from writing over
    their data.
 
  - New seq_buf_hex_dump() that lets users use the hex_dump() in their
    seq_buf usage.
 
  - Notifications now added to tracing_max_latency to allow user space
    to know when a new max latency is hit by one of the latency tracers.
 
  - Wider spread use of generic compare operations for use of bsearch and
    friends.
 
  - More synthetic event fields may be defined (32 up from 16)
 
  - Use of xarray for architectures with sparse system calls, for the
    system call trace events.
 
 This along with small clean ups and fixes.
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Merge tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New tracing features:

   - New PERMANENT flag to ftrace_ops when attaching a callback to a
     function.

     As /proc/sys/kernel/ftrace_enabled when set to zero will disable
     all attached callbacks in ftrace, this has a detrimental impact on
     live kernel tracing, as it disables all that it patched. If a
     ftrace_ops is registered to ftrace with the PERMANENT flag set, it
     will prevent ftrace_enabled from being disabled, and if
     ftrace_enabled is already disabled, it will prevent a ftrace_ops
     with PREMANENT flag set from being registered.

   - New register_ftrace_direct().

     As eBPF would like to register its own trampolines to be called by
     the ftrace nop locations directly, without going through the ftrace
     trampoline, this function has been added. This allows for eBPF
     trampolines to live along side of ftrace, perf, kprobe and live
     patching. It also utilizes the ftrace enabled_functions file that
     keeps track of functions that have been modified in the kernel, to
     allow for security auditing.

   - Allow for kernel internal use of ftrace instances.

     Subsystems in the kernel can now create and destroy their own
     tracing instances which allows them to have their own tracing
     buffer, and be able to record events without worrying about other
     users from writing over their data.

   - New seq_buf_hex_dump() that lets users use the hex_dump() in their
     seq_buf usage.

   - Notifications now added to tracing_max_latency to allow user space
     to know when a new max latency is hit by one of the latency
     tracers.

   - Wider spread use of generic compare operations for use of bsearch
     and friends.

   - More synthetic event fields may be defined (32 up from 16)

   - Use of xarray for architectures with sparse system calls, for the
     system call trace events.

  This along with small clean ups and fixes"

* tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (51 commits)
  tracing: Enable syscall optimization for MIPS
  tracing: Use xarray for syscall trace events
  tracing: Sample module to demonstrate kernel access to Ftrace instances.
  tracing: Adding new functions for kernel access to Ftrace instances
  tracing: Fix Kconfig indentation
  ring-buffer: Fix typos in function ring_buffer_producer
  ftrace: Use BIT() macro
  ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured
  ftrace: Rename ftrace_graph_stub to ftrace_stub_graph
  ftrace: Add a helper function to modify_ftrace_direct() to allow arch optimization
  ftrace: Add helper find_direct_entry() to consolidate code
  ftrace: Add another check for match in register_ftrace_direct()
  ftrace: Fix accounting bug with direct->count in register_ftrace_direct()
  ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"
  tracing: Increase SYNTH_FIELDS_MAX for synthetic_events
  ftrace/samples: Add a sample module that implements modify_ftrace_direct()
  ftrace: Add modify_ftrace_direct()
  tracing: Add missing "inline" in stub function of latency_fsnotify()
  tracing: Remove stray tab in TRACE_EVAL_MAP_FILE's help text
  tracing: Use seq_buf_hex_dump() to dump buffers
  ...
2019-11-27 11:42:01 -08:00
Alexander Shishkin
87ff16007c intel_th: Document software sinks
Add documentation for the software sinks API of the MSU driver and the
msu-sink module in particular.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20191114064201.43089-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-14 14:48:49 +08:00
Sebastian Andrzej Siewior
9c34fc4b7e tracing: Use CONFIG_PREEMPTION
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Add additional header output for PREEMPT_RT.
Link: http://lkml.kernel.org/r/20191015191821.11479-34-bigeasy@linutronix.de

Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:37:28 -05:00
Mike Leach
f0ae2cfae5 coresight: etm4x: docs: Adds detailed document for programming etm4x.
Add in detailed programmers reference for users wanting to program the
CoreSight ETM 4.x driver using sysfs.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-11-07 13:17:26 -07:00
Mike Leach
8adf42e293 coresight: docs: Create common sub-directory for coresight trace.
There are two files in the Documentation/trace directory relating to
coresight, with more to follow, so create a Documentation/trace/coresight
directory and move existing files there. Fixup index to reference
new location.

Update MAINTAINERS to reference this sub-directory rather than the
individual files.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-11-07 13:17:26 -07:00
Miroslav Benes
7162431dcf ftrace: Introduce PERMANENT ftrace_ops flag
Livepatch uses ftrace for redirection to new patched functions. It means
that if ftrace is disabled, all live patched functions are disabled as
well. Toggling global 'ftrace_enabled' sysctl thus affect it directly.
It is not a problem per se, because only administrator can set sysctl
values, but it still may be surprising.

Introduce PERMANENT ftrace_ops flag to amend this. If the
FTRACE_OPS_FL_PERMANENT is set on any ftrace ops, the tracing cannot be
disabled by disabling ftrace_enabled. Equally, a callback with the flag
set cannot be registered if ftrace_enabled is disabled.

Link: http://lkml.kernel.org/r/20191016113316.13415-2-mbenes@suse.cz

Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-04 09:33:15 -05:00
Linus Torvalds
45979a956b Tracing updates:
- Addition of multiprobes to kprobe and uprobe events
    Allows for more than one probe attached to the same location
 
  - Addition of adding immediates to probe parameters
 
  - Clean up of the recordmcount.c code. This brings us closer
    to merging recordmcount into objtool, and reuse code.
 
  - Other small clean ups
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Merge tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Addition of multiprobes to kprobe and uprobe events (allows for more
   than one probe attached to the same location)

 - Addition of adding immediates to probe parameters

 - Clean up of the recordmcount.c code. This brings us closer to merging
   recordmcount into objtool, and reuse code.

 - Other small clean ups

* tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  selftests/ftrace: Update kprobe event error testcase
  tracing/probe: Reject exactly same probe event
  tracing/probe: Fix to allow user to enable events on unloaded modules
  selftests/ftrace: Select an existing function in kprobe_eventname test
  tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink()
  tracing: Make sure variable reference alias has correct var_ref_idx
  tracing: Be more clever when dumping hex in __print_hex()
  ftrace: Simplify ftrace hash lookup code in clear_func_from_hash()
  tracing: Add "gfp_t" support in synthetic_events
  tracing: Rename tracing_reset() to tracing_reset_cpu()
  tracing: Document the stack trace algorithm in the comments
  tracing/arm64: Have max stack tracer handle the case of return address after data
  recordmcount: Clarify what cleanup() does
  recordmcount: Remove redundant cleanup() calls
  recordmcount: Kernel style formatting
  recordmcount: Kernel style function signature formatting
  recordmcount: Rewrite error/success handling
  selftests/ftrace: Add syntax error test for multiprobe
  selftests/ftrace: Add syntax error test for immediates
  selftests/ftrace: Add a testcase for kprobe multiprobe event
  ...
2019-09-20 11:19:48 -07:00
Peter Wu
f12fcca653 docs: ftrace: clarify when tracing is disabled by the trace file
The current text could mislead the user into believing that only read()
disables tracing. Clarify that any open() call that requests read access
disables tracing.

Link: https://lkml.kernel.org/r/CAADnVQ+hU6QOC_dPmpjnuv=9g4SQEeaMEMqXOS2WpMj=q=LdiQ@mail.gmail.com
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-09-02 07:14:53 -06:00
Masami Hiramatsu
6218bf9f4d tracing/probe: Add immediate parameter support
Add immediate value parameter (\1234) support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching from memory
or register.

This feature looks odd, but imagine when you put a probe
on a code to trace some data. If the code is compiled into
2 instructions and 1 instruction has a value but other has
nothing since it is optimized out.
In that case, you can not fold those into one event, even
if ftrace supported multiple probes on one event.
With this feature, you can set a dummy value like
foo=\deadbeef instead of something like foo=%di.

Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:39 -04:00
Phong Tran
fe13225fdc Documentation: coresight: convert txt to rst
This changes from plain text to reStructuredText as suggestion
in doc-guide [1]

[1] https://www.kernel.org/doc/html/latest/doc-guide/sphinx.html

Some adaptations such as: literal block, ``inline literal`` and
alignment text,...

Signed-off-by: Phong Tran <tranmanphong@gmail.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-31 13:13:45 -06:00
Linus Torvalds
818e95c768 The main changes in this release include:
- Add user space specific memory reading for kprobes
  - Allow kprobes to be executed earlier in boot
 
 The rest are mostly just various clean ups and small fixes.
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Merge tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The main changes in this release include:

   - Add user space specific memory reading for kprobes

   - Allow kprobes to be executed earlier in boot

  The rest are mostly just various clean ups and small fixes"

* tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
  tracing: Make trace_get_fields() global
  tracing: Let filter_assign_type() detect FILTER_PTR_STRING
  tracing: Pass type into tracing_generic_entry_update()
  ftrace/selftest: Test if set_event/ftrace_pid exists before writing
  ftrace/selftests: Return the skip code when tracing directory not configured in kernel
  tracing/kprobe: Check registered state using kprobe
  tracing/probe: Add trace_event_call accesses APIs
  tracing/probe: Add probe event name and group name accesses APIs
  tracing/probe: Add trace flag access APIs for trace_probe
  tracing/probe: Add trace_event_file access APIs for trace_probe
  tracing/probe: Add trace_event_call register API for trace_probe
  tracing/probe: Add trace_probe init and free functions
  tracing/uprobe: Set print format when parsing command
  tracing/kprobe: Set print format right after parsed command
  kprobes: Fix to init kprobes in subsys_initcall
  tracepoint: Use struct_size() in kmalloc()
  ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS
  ftrace: Enable trampoline when rec count returns back to one
  tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline
  tracing: Make a separate config for trace event self tests
  ...
2019-07-18 11:51:00 -07:00
Linus Torvalds
fb4da215ed pci-v5.3-changes
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Merge tag 'pci-v5.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "Enumeration changes:

   - Evaluate PCI Boot Configuration _DSM to learn if firmware wants us
     to preserve its resource assignments (Benjamin Herrenschmidt)

   - Simplify resource distribution (Nicholas Johnson)

   - Decode 32 GT/s link speed (Gustavo Pimentel)

  Virtualization:

   - Fix incorrect caching of VF config space size (Alex Williamson)

   - Fix VF driver probing sysfs knobs (Alex Williamson)

  Peer-to-peer DMA:

   - Fix dma_virt_ops check (Logan Gunthorpe)

  Altera host bridge driver:

   - Allow building as module (Ley Foon Tan)

  Armada 8K host bridge driver:

   - add PHYs support (Miquel Raynal)

  DesignWare host bridge driver:

   - Export APIs to support removable loadable module (Vidya Sagar)

   - Enable Relaxed Ordering erratum workaround only on Tegra20 &
     Tegra30 (Vidya Sagar)

  Hyper-V host bridge driver:

   - Fix use-after-free in eject (Dexuan Cui)

  Mobiveil host bridge driver:

   - Clean up and fix many issues, including non-identify mapped
     windows, 64-bit windows, multi-MSI, class code, INTx clearing (Hou
     Zhiqiang)

  Qualcomm host bridge driver:

   - Use clk bulk API for 2.4.0 controllers (Bjorn Andersson)

   - Add QCS404 support (Bjorn Andersson)

   - Assert PERST for at least 100ms (Niklas Cassel)

  R-Car host bridge driver:

   - Add r8a774a1 DT support (Biju Das)

  Tegra host bridge driver:

   - Add support for Gen2, opportunistic UpdateFC and ACK (PCIe protocol
     details) AER, GPIO-based PERST# (Manikanta Maddireddy)

   - Fix many issues, including power-on failure cases, interrupt
     masking in suspend, UPHY settings, AFI dynamic clock gating,
     pending DLL transactions (Manikanta Maddireddy)

  Xilinx host bridge driver:

   - Fix NWL Multi-MSI programming (Bharat Kumar Gogada)

  Endpoint support:

   - Fix 64bit BAR support (Alan Mikhak)

   - Fix pcitest build issues (Alan Mikhak, Andy Shevchenko)

  Bug fixes:

   - Fix NVIDIA GPU multi-function power dependencies (Abhishek Sahu)

   - Fix NVIDIA GPU HDA enablement issue (Lukas Wunner)

   - Ignore lockdep for sysfs "remove" (Marek Vasut)

  Misc:

   - Convert docs to reST (Changbin Du, Mauro Carvalho Chehab)"

* tag 'pci-v5.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (107 commits)
  PCI: Enable NVIDIA HDA controllers
  tools: PCI: Fix installation when `make tools/pci_install`
  PCI: dwc: pci-dra7xx: Fix compilation when !CONFIG_GPIOLIB
  PCI: Fix typos and whitespace errors
  PCI: mobiveil: Fix INTx interrupt clearing in mobiveil_pcie_isr()
  PCI: mobiveil: Fix infinite-loop in the INTx handling function
  PCI: mobiveil: Move PCIe PIO enablement out of inbound window routine
  PCI: mobiveil: Add upper 32-bit PCI base address setup in inbound window
  PCI: mobiveil: Add upper 32-bit CPU base address setup in outbound window
  PCI: mobiveil: Mask out hardcoded bits in inbound/outbound windows setup
  PCI: mobiveil: Clear the control fields before updating it
  PCI: mobiveil: Add configured inbound windows counter
  PCI: mobiveil: Fix the valid check for inbound and outbound windows
  PCI: mobiveil: Clean-up program_{ib/ob}_windows()
  PCI: mobiveil: Remove an unnecessary return value check
  PCI: mobiveil: Fix error return values
  PCI: mobiveil: Refactor the MEM/IO outbound window initialization
  PCI: mobiveil: Make some register updates more readable
  PCI: mobiveil: Reformat the code for readability
  dt-bindings: PCI: mobiveil: Change gpio_slave and apb_csr to optional
  ...
2019-07-15 20:44:49 -07:00
Mauro Carvalho Chehab
7e6294cdc0 docs: trace: add a missing blank line
Sphinx expects a blank line after a literal block markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-20 14:05:46 -06:00
Mauro Carvalho Chehab
151f4e2bdc docs: power: convert docs to ReST and rename to *.rst
Convert the PM documents to ReST, in order to allow them to
build with Sphinx.

The conversion is actually:
  - add blank lines and indentation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
2019-06-14 16:08:36 -05:00
Suzuki K Poulose
cd84d63a29 Documentation: coresight: Update the generic device names
Update the documentation to reflect the new naming scheme with
latest changes.

Reported-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:43:21 -06:00
Lecopzer Chen
78a89463a3 Documentation: {u,k}probes: add tracing_on before tracing
After following the document step by step, the `cat trace` can't be
worked without enabling tracing_on and might mislead newbies about
the functionality.

Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-07 11:56:51 -06:00
Masanari Iida
fe4ec72cca docs: tracing: Fix typos in histogram.rst
This patch fixes some spelling typos in histogram.rst

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-29 15:49:01 -06:00
Masami Hiramatsu
970988e19e tracing/kprobe: Add kprobe_event= boot parameter
Add kprobe_event= boot parameter to define kprobe events
at boot time.
The definition syntax is similar to tracefs/kprobe_events
interface, but use ',' and ';' instead of ' ' and '\n'
respectively. e.g.

  kprobe_event=p,vfs_read,$arg1,$arg2

This puts a probe on vfs_read with argument1 and 2, and
enable the new event.

Link: http://lkml.kernel.org/r/155851395498.15728.830529496248543583.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:43 -04:00
Masami Hiramatsu
e65f7ae7f4 tracing/probe: Support user-space dereference
Support user-space dereference syntax for probe event arguments
to dereference the data-structure or array in user-space.

The syntax is just adding 'u' before an offset value.

 +|-u<OFFSET>(<FETCHARG>)

e.g. +u8(%ax), +u0(+0(%si))

For example, if you probe do_sched_setscheduler(pid, policy,
param) and record param->sched_priority, you can add new
probe as below;

 p do_sched_setscheduler priority=+u0($arg3)

Note that kprobe event provides this and it doesn't change the
dereference method automatically because we do not know whether
the given address is in userspace or kernel on some archs.

So as same as "ustring", this is an option for user, who has to
carefully choose the dereference method.

Link: http://lkml.kernel.org/r/155789872187.26965.4468456816590888687.stgit@devnote2

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00
Masami Hiramatsu
88903c4643 tracing/probe: Add ustring type for user-space string
Add "ustring" type for fetching user-space string from kprobe event.
User can specify ustring type at uprobe event, and it is same as
"string" for uprobe.

Note that probe-event provides this option but it doesn't choose the
correct type automatically since we have not way to decide the address
is in user-space or not on some arch (and on some other arch, you can
fetch the string by "string" type). So user must carefully check the
target code (e.g. if you see __user on the target variable) and
use this new type.

Link: http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2

Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00
Linus Torvalds
d2d8b14604 The major changes in this tracing update includes:
- Removing of non-DYNAMIC_FTRACE from 32bit x86
 
  - Removing of mcount support from x86
 
  - Emulating a call from int3 on x86_64, fixes live kernel patching
 
  - Consolidated Tracing Error logs file
 
 Minor updates:
 
  - Removal of klp_check_compiler_support()
 
  - kdb ftrace dumping output changes
 
  - Accessing and creating ftrace instances from inside the kernel
 
  - Clean up of #define if macro
 
  - Introduction of TRACE_EVENT_NOP() to disable trace events based on config
    options
 
 And other minor fixes and clean ups
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Merge tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The major changes in this tracing update includes:

   - Removal of non-DYNAMIC_FTRACE from 32bit x86

   - Removal of mcount support from x86

   - Emulating a call from int3 on x86_64, fixes live kernel patching

   - Consolidated Tracing Error logs file

  Minor updates:

   - Removal of klp_check_compiler_support()

   - kdb ftrace dumping output changes

   - Accessing and creating ftrace instances from inside the kernel

   - Clean up of #define if macro

   - Introduction of TRACE_EVENT_NOP() to disable trace events based on
     config options

  And other minor fixes and clean ups"

* tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
  x86: Hide the int3_emulate_call/jmp functions from UML
  livepatch: Remove klp_check_compiler_support()
  ftrace/x86: Remove mcount support
  ftrace/x86_32: Remove support for non DYNAMIC_FTRACE
  tracing: Simplify "if" macro code
  tracing: Fix documentation about disabling options using trace_options
  tracing: Replace kzalloc with kcalloc
  tracing: Fix partial reading of trace event's id file
  tracing: Allow RCU to run between postponed startup tests
  tracing: Fix white space issues in parse_pred() function
  tracing: Eliminate const char[] auto variables
  ring-buffer: Fix mispelling of Calculate
  tracing: probeevent: Fix to make the type of $comm string
  tracing: probeevent: Do not accumulate on ret variable
  tracing: uprobes: Re-enable $comm support for uprobe events
  ftrace/x86_64: Emulate call function while updating in breakpoint handler
  x86_64: Allow breakpoints to emulate call instructions
  x86_64: Add gap to int3 to allow for call emulation
  tracing: kdb: Allow ftdump to skip all but the last few entries
  tracing: Add trace_total_entries() / trace_total_entries_cpu()
  ...
2019-05-15 16:05:47 -07:00
Kirill Tkhai
886cf1901d mm: move recent_rotated pages calculation to shrink_inactive_list()
Patch series "mm: Generalize putback functions"]

putback_inactive_pages() and move_active_pages_to_lru() are almost
similar, so this patchset merges them ina single function.

This patch (of 4):

The patch moves the calculation from putback_inactive_pages() to
shrink_inactive_list().  This makes putback_inactive_pages() looking more
similar to move_active_pages_to_lru().

To do that, we account activated pages in reclaim_stat::nr_activate.
Since a page may change its LRU type from anon to file cache inside
shrink_page_list() (see ClearPageSwapBacked()), we have to account pages
for the both types.  So, nr_activate becomes an array.

Previously we used nr_activate to account PGACTIVATE events, but now we
account them into pgactivate variable (since they are about number of
pages in general, not about sum of hpage_nr_pages).

Link: http://lkml.kernel.org/r/155290127956.31489.3393586616054413298.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 09:47:45 -07:00
Linus Torvalds
1fb3b526df Some late arriving documentation changes. In particular, this contains the
conversion of the x86 docs to RST, which has been in the works for some
 time but needed a couple of final tweaks.
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Merge tag 'docs-5.2a' of git://git.lwn.net/linux

Pull more documentation updates from Jonathan Corbet:
 "Some late arriving documentation changes. In particular, this contains
  the conversion of the x86 docs to RST, which has been in the works for
  some time but needed a couple of final tweaks"

* tag 'docs-5.2a' of git://git.lwn.net/linux: (29 commits)
  Documentation: x86: convert x86_64/machinecheck to reST
  Documentation: x86: convert x86_64/cpu-hotplug-spec to reST
  Documentation: x86: convert x86_64/fake-numa-for-cpusets to reST
  Documentation: x86: convert x86_64/5level-paging.txt to reST
  Documentation: x86: convert x86_64/mm.txt to reST
  Documentation: x86: convert x86_64/uefi.txt to reST
  Documentation: x86: convert x86_64/boot-options.txt to reST
  Documentation: x86: convert i386/IO-APIC.txt to reST
  Documentation: x86: convert usb-legacy-support.txt to reST
  Documentation: x86: convert orc-unwinder.txt to reST
  Documentation: x86: convert resctrl_ui.txt to reST
  Documentation: x86: convert microcode.txt to reST
  Documentation: x86: convert pti.txt to reST
  Documentation: x86: convert amd-memory-encryption.txt to reST
  Documentation: x86: convert intel_mpx.txt to reST
  Documentation: x86: convert protection-keys.txt to reST
  Documentation: x86: convert pat.txt to reST
  Documentation: x86: convert mtrr.txt to reST
  Documentation: x86: convert tlb.txt to reST
  Documentation: x86: convert zero-page.txt to reST
  ...
2019-05-10 13:24:53 -04:00
Tzvetomir Stoyanov
39a39d5b6b Documentation/trace: Add clarification how histogram onmatch works
The current trace documentation, the section describing histogram's "onmatch"
is not straightforward enough about how this action is applied. It is not
clear what criteria are used to "match" both events. A short note is added,
describing what exactly is compared in order to match the events.

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[jc: fixed trivial conflict with docs-next]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-08 14:32:05 -06:00
Linus Torvalds
8c79f4cd44 A reasonably busy cycle for docs, including:
- Lots of work on the Chinese and Italian translations
  - Some license-rules clarifications from Christoph
  - Various build-script fixes
  - A new document on memory models
  - RST conversion of the live-patching docs
  - The usual collection of typo fixes and corrections.
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Merge tag 'docs-5.2' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "A reasonably busy cycle for docs, including:

   - Lots of work on the Chinese and Italian translations

   - Some license-rules clarifications from Christoph

   - Various build-script fixes

   - A new document on memory models

   - RST conversion of the live-patching docs

   - The usual collection of typo fixes and corrections"

* tag 'docs-5.2' of git://git.lwn.net/linux: (140 commits)
  docs/livepatch: Unify style of livepatch documentation in the ReST format
  docs: livepatch: convert docs to ReST and rename to *.rst
  scripts/documentation-file-ref-check: detect broken :doc:`foo`
  scripts/documentation-file-ref-check: don't parse Next/ dir
  LICENSES: Rename other to deprecated
  LICENSES: Clearly mark dual license only licenses
  docs: Don't reference the ZLib license in license-rules.rst
  docs/vm: Minor editorial changes in the THP and hugetlbfs
  docs/vm: add documentation of memory models
  doc:it_IT: translation alignment
  doc: fix typo in PGP guide
  dontdiff: update with Kconfig build artifacts
  docs/zh_CN: fix typos in 1.Intro.rst file
  docs/zh_CN: redirect CoC docs to Chinese version
  doc: mm: migration doesn't use FOLL_SPLIT anymore
  docs: doc-guide: remove the extension from .rst files
  doc: kselftest: Fix KBUILD_OUTPUT usage instructions
  docs: trace: fix some Sphinx warnings
  docs: speculation.txt: mark example blocks as such
  docs: ntb.txt: add blank lines to clean up some Sphinx warnings
  ...
2019-05-08 12:42:50 -07:00
Alexander Shishkin
85d49eb130 intel_th: SPDX-ify the documentation
Add the SPDX header to the Intel TH documentation.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-03 18:14:29 +02:00
Mauro Carvalho Chehab
3df5ffd2e5 docs: trace: fix some Sphinx warnings
There are some warnings produced when building trace. Fix them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-04-16 09:08:32 -06:00
Tom Zanussi
26a9449179 tracing: Add tracing/error_log Documentation
Move most of the hist trigger extended error documentation to
ftrace.rst and expand on it to fully document tracing/error_log.

Link: http://lkml.kernel.org/r/c5d53c8f643ef6844d6ad8d0200c116936730b01.1554072478.git.tom.zanussi@linux.intel.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-08 09:22:50 -04:00
Srikar Dronamraju
b689269bd1 doc: trace: Fix documentation for uprobe_profile
uprobe_profile has filename and number of probe hits information for
each uprobe event. The documentation erroneously talks about probe
mis-hits. Update the documentation to the correct information.

Link: http://lkml.kernel.org/r/1550557168-12345-1-git-send-email-srikar@linux.vnet.ibm.com

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: KAUSTUBH RAJENDRA WELANKAR <f20160095@hyderabad.bits-pilani.ac.in>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-21 10:28:55 -05:00
Tom Zanussi
e91eefd731 tracing: Add alternative synthetic event trace action syntax
Add a 'trace(synthetic_event_name, params)' alternative to
synthetic_event_name(params).

Currently, the syntax used for generating synthetic events is to
invoke synthetic_event_name(params) i.e. use the synthetic event name
as a function call.

Users requested a new form that more explicitly shows that the
synthetic event is in effect being traced.  In this version, a new
'trace()' keyword is used, and the synthetic event name is passed in
as the first argument.

In addition, for the sake of consistency with other actions, change
the documention to emphasize the trace() form over the function-call
form, which remains documented as equivalent.

Link: http://lkml.kernel.org/r/d082773e50232a001480cf837679a1e01c1a2eb7.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi
ff0d35e2e1 tracing: Add hist trigger onchange() handler Documentation
Add Documentation for the hist:onchange($var) handler.

Link: http://lkml.kernel.org/r/ab54b7383b265609fda52648a8fbfbd2631a640f.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi
fd451a3d92 tracing: Add hist trigger snapshot() action Documentation
Add Documentation for the hist:handlerXXX($var).snapshot() action.

Link: http://lkml.kernel.org/r/445861d7822cd4b6aeaea1cecfcdbda466502148.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:07 -05:00
Tom Zanussi
5032b38189 tracing: Make hist trigger Documentation better reflect actions/handlers
The action/handler code refactoring didn't change the action/handler
syntax, but did generalize it - the Documentation should reflect that.

Link: http://lkml.kernel.org/r/c2fe4144678829c70cad67aaa847dca27d57cb83.1550100284.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:06 -05:00
Steven Rostedt (VMware)
f79b3f3385 ftrace: Allow enabling of filters via index of available_filter_functions
Enabling of large number of functions by echoing in a large subset of the
functions in available_filter_functions can take a very long time. The
process requires testing all functions registered by the function tracer
(which is in the 10s of thousands), and doing a kallsyms lookup to convert
the ip address into a name, then comparing that name with the string passed
in.

When a function causes the function tracer to crash the system, a binary
bisect of the available_filter_functions can be done to find the culprit.
But this requires passing in half of the functions in
available_filter_functions over and over again, which makes it basically a
O(n^2) operation. With 40,000 functions, that ends up bing 1,600,000,000
opertions! And enabling this can take over 20 minutes.

As a quick speed up, if a number is passed into one of the filter files,
instead of doing a search, it just enables the function at the corresponding
line of the available_filter_functions file. That is:

 # echo 50 > set_ftrace_filter
 # cat set_ftrace_filter
 x86_pmu_commit_txn

 # head -50 available_filter_functions | tail -1
 x86_pmu_commit_txn

This allows setting of half the available_filter_functions to take place in
less than a second!

 # time seq 20000 > set_ftrace_filter
 real    0m0.042s
 user    0m0.005s
 sys     0m0.015s

 # wc -l set_ftrace_filter
 20000 set_ftrace_filter

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-15 13:10:09 -05:00
Changbin Du
88d380eb06 tracing/doc: Add latency tracer funcgraph example
This add an example about how to use funcgraph with latency tracers.

Link: http://lkml.kernel.org/r/20190101154614.8887-6-changbin.du@gmail.com

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-06 11:56:19 -05:00
Rafael J. Wysocki
343e60e52a Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep'
* pm-cpuidle:
  doc: trace: fix reference to cpuidle documentation file
  cpuidle / Documentation: Update cpuidle MAINTAINERS entry

* pm-cpufreq:
  cpufreq: scmi: Fix frequency invariance in slow path
  cpufreq: check if policy is inactive early in __cpufreq_get()
  cpufreq: scpi/scmi: Fix freeing of dynamic OPPs
  cpufreq / Documentation: Update cpufreq MAINTAINERS entry

* pm-sleep:
  PM: sleep: call devfreq suspend/resume
2019-01-11 10:09:51 +01:00
Otto Sabart
7604bf0920 doc: trace: fix reference to cpuidle documentation file
Old cpuidle/sysfs.txt file was replaced in aa5eee355b. So, refer to
an updated file.

Fixes: aa5eee355b (Documentation: admin-guide: PM: Add cpuidle document)
Signed-off-by: Otto Sabart <ottosabart@seberm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-09 11:44:30 +01:00