History log of /linux/Documentation/trace/ftrace.rst (Results 1 – 25 of 381)
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# 36ec807b 20-Sep-2024 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 6.12 merge window.


Revision tags: v6.11, v6.11-rc7, v6.11-rc6, v6.11-rc5, v6.11-rc4, v6.11-rc3, v6.11-rc2, v6.11-rc1
# 3daee2e4 16-Jul-2024 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v6.10' into next

Sync up with mainline to bring in device_for_each_child_node_scoped()
and other newer APIs.


# af9c191a 22-Sep-2024 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'trace-ring-buffer-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ring-buffer updates from Steven Rostedt:

- tracing/ring-buffer: persistent buffer across

Merge tag 'trace-ring-buffer-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ring-buffer updates from Steven Rostedt:

- tracing/ring-buffer: persistent buffer across reboots

This allows for the tracing instance ring buffer to stay persistent
across reboots. The way this is done is by adding to the kernel
command line:

trace_instance=boot_map@0x285400000:12M

This will reserve 12 megabytes at the address 0x285400000, and then
map the tracing instance "boot_map" ring buffer to that memory. This
will appear as a normal instance in the tracefs system:

/sys/kernel/tracing/instances/boot_map

A user could enable tracing in that instance, and on reboot or kernel
crash, if the memory is not wiped by the firmware, it will recreate
the trace in that instance. For example, if one was debugging a
shutdown of a kernel reboot:

# cd /sys/kernel/tracing
# echo function > instances/boot_map/current_tracer
# reboot
[..]
# cd /sys/kernel/tracing
# tail instances/boot_map/trace
swapper/0-1 [000] d..1. 164.549800: restore_boot_irq_mode <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549801: native_restore_boot_irq_mode <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549802: disconnect_bsp_APIC <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549811: hpet_disable <-native_machine_shutdown
swapper/0-1 [000] d..1. 164.549812: iommu_shutdown_noop <-native_machine_restart
swapper/0-1 [000] d..1. 164.549813: native_machine_emergency_restart <-__do_sys_reboot
swapper/0-1 [000] d..1. 164.549813: tboot_shutdown <-native_machine_emergency_restart
swapper/0-1 [000] d..1. 164.549820: acpi_reboot <-native_machine_emergency_restart
swapper/0-1 [000] d..1. 164.549821: acpi_reset <-acpi_reboot
swapper/0-1 [000] d..1. 164.549822: acpi_os_write_port <-acpi_reboot

On reboot, the buffer is examined to make sure it is valid. The
validation check even steps through every event to make sure the meta
data of the event is correct. If any test fails, it will simply reset
the buffer, and the buffer will be empty on boot.

- Allow the tracing persistent boot buffer to use the "reserve_mem"
option

Instead of having the admin find a physical address to store the
persistent buffer, which can be very tedious if they have to
administrate several different machines, allow them to use the
"reserve_mem" option that will find a location for them. It is not as
reliable because of KASLR, as the loading of the kernel in different
locations can cause the memory allocated to be inconsistent. Booting
with "nokaslr" can make reserve_mem more reliable.

- Have function graph tracer handle offsets from a previous boot.

The ring buffer output from a previous boot may have different
addresses due to kaslr. Have the function graph tracer handle these
by using the delta from the previous boot to the new boot address
space.

- Only reset the saved meta offset when the buffer is started or reset

In the persistent memory meta data, it holds the previous address
space information, so that it can calculate the delta to have
function tracing work. But this gets updated after being read to hold
the new address space. But if the buffer isn't used for that boot, on
reboot, the delta is now calculated from the previous boot and not
the boot that holds the data in the ring buffer. This causes the
functions not to be shown. Do not save the address space information
of the current kernel until it is being recorded.

- Add a magic variable to test the valid meta data

Add a magic variable in the meta data that can also be used for
validation. The validator of the previous buffer doesn't need this
magic data, but it can be used if the meta data is changed by a new
kernel, which may have the same format that passes the validator but
is used differently. This magic number can also be used as a
"versioning" of the meta data.

- Align user space mapped ring buffer sub buffers to improve TLB
entries

Linus mentioned that the mapped ring buffer sub buffers were
misaligned between the meta page and the sub-buffers, so that if the
sub-buffers were bigger than PAGE_SIZE, it wouldn't allow the TLB to
use bigger entries.

- Add new kernel command line "traceoff" to disable tracing on boot for
instances

If tracing is enabled for a boot instance, there needs a way to be
able to disable it on boot so that new events do not get entered into
the ring buffer and be mixed with events from a previous boot, as
that can be confusing.

- Allow trace_printk() to go to other instances

Currently, trace_printk() can only go to the top level instance. When
debugging with a persistent buffer, it is really useful to be able to
add trace_printk() to go to that buffer, so that you have access to
them after a crash.

- Do not use "bin_printk()" for traces to a boot instance

The bin_printk() saves only a pointer to the printk format in the
ring buffer, as the reader of the buffer can still have access to it.
But this is not the case if the buffer is from a previous boot. If
the trace_printk() is going to a "persistent" buffer, it will use the
slower version that writes the printk format into the buffer.

- Add command line option to allow trace_printk() to go to an instance

Allow the kernel command line to define which instance the
trace_printk() goes to, instead of forcing the admin to set it for
every boot via the tracefs options.

- Start a document that explains how to use tracefs to debug the kernel

- Add some more kernel selftests to test user mapped ring buffer

* tag 'trace-ring-buffer-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (28 commits)
selftests/ring-buffer: Handle meta-page bigger than the system
selftests/ring-buffer: Verify the entire meta-page padding
tracing/Documentation: Start a document on how to debug with tracing
tracing: Add option to set an instance to be the trace_printk destination
tracing: Have trace_printk not use binary prints if boot buffer
tracing: Allow trace_printk() to go to other instance buffers
tracing: Add "traceoff" flag to boot time tracing instances
ring-buffer: Align meta-page to sub-buffers for improved TLB usage
ring-buffer: Add magic and struct size to boot up meta data
ring-buffer: Don't reset persistent ring-buffer meta saved addresses
tracing/fgraph: Have fgraph handle previous boot function addresses
tracing: Allow boot instances to use reserve_mem boot memory
tracing: Fix ifdef of snapshots to not prevent last_boot_info file
ring-buffer: Use vma_pages() helper function
tracing: Fix NULL vs IS_ERR() check in enable_instances()
tracing: Add last boot delta offset for stack traces
tracing: Update function tracing output for previous boot buffer
tracing: Handle old buffer mappings for event strings and functions
tracing/ring-buffer: Add last_boot_info file to boot instance
ring-buffer: Save text and data locations in mapped meta data
...

show more ...


# ef2bd81d 23-Aug-2024 Steven Rostedt <rostedt@goodmis.org>

tracing: Add option to set an instance to be the trace_printk destination

Add a option "trace_printk_dest" that will make the tracing instance the
location that trace_printk() will go to. This is us

tracing: Add option to set an instance to be the trace_printk destination

Add a option "trace_printk_dest" that will make the tracing instance the
location that trace_printk() will go to. This is useful if the
trace_printk or one of the top level tracers is too noisy and there's a
need to separate the two. Then an instance can be created, the
trace_printk can be set to go there instead, where it will not be lost in
the noise of the top level tracer.

Note, only one instance can be the destination of trace_printk at a time.
If an instance sets this flag, the instance that had it set will have it
cleared. There is always one instance that has this set. By default, that
is the top instance. This flag cannot be cleared from the top instance.
Doing so will result in an -EINVAL. The only way this flag can be cleared
from the top instance is by another instance setting it.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineeth Pillai <vineeth@bitbyteword.org>
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Alexander Aring <aahringo@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>
Link: https://lore.kernel.org/20240823014019.545459018@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

show more ...


# a23e1966 15-Jul-2024 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 6.11 merge window.


Revision tags: v6.10, v6.10-rc7, v6.10-rc6, v6.10-rc5, v6.10-rc4, v6.10-rc3, v6.10-rc2
# 6f47c7ae 28-May-2024 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v6.9' into next

Sync up with the mainline to bring in the new cleanup API.


# afeea275 04-Jul-2024 Maxime Ripard <mripard@kernel.org>

Merge drm-misc-next-2024-07-04 into drm-misc-next-fixes

Let's start the drm-misc-next-fixes cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>


# d754ed28 19-Jun-2024 Jani Nikula <jani.nikula@intel.com>

Merge drm/drm-next into drm-intel-next

Sync to v6.10-rc3.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>


# 89aa02ed 12-Jun-2024 Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-xe-next

Needed to get tracing cleanup and add mmio tracing series.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>


# 92815da4 12-Jun-2024 Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Merge remote-tracking branch 'drm-misc/drm-misc-next' into HEAD

Merge drm-misc-next tree into the msm-next tree in order to be able to
use HDMI connector framework for the MSM HDMI driver.


# 375c4d15 27-May-2024 Maxime Ripard <mripard@kernel.org>

Merge drm/drm-next into drm-misc-next

Let's start the new release cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>


Revision tags: v6.10-rc1
# 60a2f25d 16-May-2024 Tvrtko Ursulin <tursulin@ursulin.net>

Merge drm/drm-next into drm-intel-gt-next

Some display refactoring patches are needed in order to allow conflict-
less merging.

Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>


# 0c8ea05e 04-Jul-2024 Peter Zijlstra <peterz@infradead.org>

Merge branch 'tip/x86/cpu'

The Lunarlake patches rely on the new VFM stuff.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>


# 594ce0b8 10-Jun-2024 Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Merge topic branches 'clkdev' and 'fixes' into for-linus


# f73a058b 28-May-2024 Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Merge remote-tracking branch 'drm/drm-fixes' into drm-misc-fixes

v6.10-rc1 is released, forward from v6.9

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>


# 621cde16 15-May-2024 Jakub Kicinski <kuba@kernel.org>

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Cross merge.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>


Revision tags: v6.9, v6.9-rc7, v6.9-rc6, v6.9-rc5, v6.9-rc4, v6.9-rc3, v6.9-rc2, v6.9-rc1, v6.8, v6.8-rc7
# 06d07429 29-Feb-2024 Jani Nikula <jani.nikula@intel.com>

Merge drm/drm-next into drm-intel-next

Sync to get the drm_printer changes to drm-intel-next.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>


# 8815da98 13-May-2024 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'docs-6.10' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
"Another not-too-busy cycle for documentation, including:

- Some build-system changes to detect

Merge tag 'docs-6.10' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
"Another not-too-busy cycle for documentation, including:

- Some build-system changes to detect the variable fonts installed by
some distributions that can break the PDF build.

- Various updates and additions to the Spanish, Chinese, Italian, and
Japanese translations.

- Update the stable-kernel rules to match modern practice

... and the usual array of corrections, updates, and typo fixes"

* tag 'docs-6.10' of git://git.lwn.net/linux: (42 commits)
cgroup: Add documentation for missing zswap memory.stat
kernel-doc: Added "*" in $type_constants2 to fix 'make htmldocs' warning.
docs:core-api: fixed typos and grammar in printk-index page
Documentation: tracing: Fix spelling mistakes
docs/zh_CN/rust: Update the translation of quick-start to 6.9-rc4
docs/zh_CN/rust: Update the translation of general-information to 6.9-rc4
docs/zh_CN/rust: Update the translation of coding-guidelines to 6.9-rc4
docs/zh_CN/rust: Update the translation of arch-support to 6.9-rc4
docs: stable-kernel-rules: fix typo sent->send
docs/zh_CN: remove two inconsistent spaces
docs: scripts/check-variable-fonts.sh: Improve commands for detection
docs: stable-kernel-rules: create special tag to flag 'no backporting'
docs: stable-kernel-rules: explain use of stable@kernel.org (w/o @vger.)
docs: stable-kernel-rules: remove code-labels tags and a indention level
docs: stable-kernel-rules: call mainline by its name and change example
docs: stable-kernel-rules: reduce redundancy
docs, kprobes: Add riscv as supported architecture
Docs: typos/spelling
docs: kernel_include.py: Cope with docutils 0.21
docs: ja_JP/howto: Catch up update in v6.8
...

show more ...


# dd29dfe7 02-May-2024 Saurav Shah <sauravshah.31@gmail.com>

Documentation: tracing: Fix spelling mistakes

Fix spelling mistakes in the documentation.

Signed-off-by: Saurav Shah <sauravshah.31@gmail.com>
Link: https://lore.kernel.org/r/20240501233659.25441-1

Documentation: tracing: Fix spelling mistakes

Fix spelling mistakes in the documentation.

Signed-off-by: Saurav Shah <sauravshah.31@gmail.com>
Link: https://lore.kernel.org/r/20240501233659.25441-1-sauravshah.31@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...


# 2e21dee6 13-Mar-2024 Jiri Kosina <jkosina@suse.com>

Merge branch 'for-6.9/amd-sfh' into for-linus

- assorted fixes and optimizations for amd-sfh (Basavaraj Natikar)

Signed-off-by: Jiri Kosina <jkosina@suse.com>


Revision tags: v6.8-rc6, v6.8-rc5
# 41c177cf 11-Feb-2024 Rob Clark <robdclark@chromium.org>

Merge tag 'drm-misc-next-2024-02-08' into msm-next

Merge the drm-misc tree to uprev MSM CI.

Signed-off-by: Rob Clark <robdclark@chromium.org>


Revision tags: v6.8-rc4, v6.8-rc3
# 4db102dc 29-Jan-2024 Maxime Ripard <mripard@kernel.org>

Merge drm/drm-next into drm-misc-next

Kickstart 6.9 development cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>


Revision tags: v6.8-rc2
# be3382ec 23-Jan-2024 Lucas De Marchi <lucas.demarchi@intel.com>

Merge drm/drm-next into drm-xe-next

Sync to v6.8-rc1.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>


# 03c11eb3 14-Feb-2024 Ingo Molnar <mingo@kernel.org>

Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

Conflicts:
arch/x86/include/asm/percpu.h
arch/x86/include/asm/text-patching.h

Signed-off-by: Ingo Molnar <mingo@k

Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

Conflicts:
arch/x86/include/asm/percpu.h
arch/x86/include/asm/text-patching.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...


# 42ac0be1 26-Jan-2024 Ingo Molnar <mingo@kernel.org>

Merge branch 'linus' into x86/mm, to refresh the branch and pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>


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