Revision tags: v6.6.67, v6.6.66, v6.6.65, v6.6.64, v6.6.63, v6.6.62, v6.6.61, v6.6.60, v6.6.59, v6.6.58, v6.6.57, v6.6.56, v6.6.55, v6.6.54, v6.6.53, v6.6.52, v6.6.51, v6.6.50, v6.6.49, v6.6.48, v6.6.47, v6.6.46, v6.6.45, v6.6.44, v6.6.43, v6.6.42, v6.6.41, v6.6.40, v6.6.39, v6.6.38, v6.6.37, v6.6.36, v6.6.35, v6.6.34, v6.6.33, v6.6.32, v6.6.31, v6.6.30, v6.6.29, v6.6.28, v6.6.27, v6.6.26, v6.6.25, v6.6.24, v6.6.23, v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12, v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8, v6.5.7, v6.5.6, v6.5.5, v6.5.4, v6.5.3 |
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c900529f |
| 12-Sep-2023 |
Thomas Zimmermann <tzimmermann@suse.de> |
Merge drm/drm-fixes into drm-misc-fixes
Forwarding to v6.6-rc1.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
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Revision tags: v6.5.2, v6.1.51, v6.5.1 |
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34232fcf |
| 01-Sep-2023 |
Linus Torvalds <torvalds@linux-foundation.org> |
Merge tag 'trace-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt: "User visible changes:
- Added a way to easier filter with cp
Merge tag 'trace-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt: "User visible changes:
- Added a way to easier filter with cpumasks:
# echo 'cpumask & CPUS{17-42}' > /sys/kernel/tracing/events/ipi_send_cpumask/filter
- Show actual size of ring buffer after modifying the ring buffer size via buffer_size_kb.
Currently it just returns what was written, but the actual size rounds up to the sub buffer size. Show that real size instead.
Major changes:
- Added "eventfs". This is the code that handles the inodes and dentries of tracefs/events directory. As there are thousands of events, and each event has several inodes and dentries that currently exist even when tracing is never used, they take up precious memory. Instead, eventfs will allocate the inodes and dentries in a JIT way (similar to what procfs does). There is now metadata that handles the events and subdirectories, and will create the inodes and dentries when they are used.
Note, I also have patches that remove the subdirectory meta data, but will wait till the next merge window before applying them. It's a little more complex, and I want to make sure the dynamic code works properly before adding more complexity, making it easier to revert if need be.
Minor changes:
- Optimization to user event list traversal
- Remove intermediate permission of tracefs files (note the intermediate permission removes all access to the files so it is not a security concern, but just a clean up)
- Add the complex fix to FORTIFY_SOURCE to the kernel stack event logic
- Other minor cleanups"
* tag 'trace-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (29 commits) tracefs: Remove kerneldoc from struct eventfs_file tracefs: Avoid changing i_mode to a temp value tracing/user_events: Optimize safe list traversals ftrace: Remove empty declaration ftrace_enable_daemon() and ftrace_disable_daemon() tracing: Remove unused function declarations tracing/filters: Document cpumask filtering tracing/filters: Further optimise scalar vs cpumask comparison tracing/filters: Optimise CPU vs cpumask filtering when the user mask is a single CPU tracing/filters: Optimise scalar vs cpumask filtering when the user mask is a single CPU tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU tracing/filters: Enable filtering the CPU common field by a cpumask tracing/filters: Enable filtering a scalar field by a cpumask tracing/filters: Enable filtering a cpumask field by another cpumask tracing/filters: Dynamically allocate filter_pred.regex test: ftrace: Fix kprobe test for eventfs eventfs: Move tracing/events to eventfs eventfs: Implement removal of meta data from eventfs eventfs: Implement functions to create files and dirs when accessed eventfs: Implement eventfs lookup, read, open functions eventfs: Implement eventfs file add functions ...
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Revision tags: v6.1.50, v6.5, v6.1.49, v6.1.48, v6.1.46, v6.1.45, v6.1.44 |
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2612e3bb |
| 07-Aug-2023 |
Rodrigo Vivi <rodrigo.vivi@intel.com> |
Merge drm/drm-next into drm-intel-next
Catching-up with drm-next and drm-intel-gt-next. It will unblock a code refactor around the platform definitions (names vs acronyms).
Signed-off-by: Rodrigo V
Merge drm/drm-next into drm-intel-next
Catching-up with drm-next and drm-intel-gt-next. It will unblock a code refactor around the platform definitions (names vs acronyms).
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
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9f771739 |
| 07-Aug-2023 |
Joonas Lahtinen <joonas.lahtinen@linux.intel.com> |
Merge drm/drm-next into drm-intel-gt-next
Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as a dependency for https://patchwork.freedesktop.org/series/1
Merge drm/drm-next into drm-intel-gt-next
Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as a dependency for https://patchwork.freedesktop.org/series/121735/
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
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Revision tags: v6.1.43, v6.1.42, v6.1.41, v6.1.40, v6.1.39 |
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e7186af7 |
| 13-Jul-2023 |
Steven Rostedt (Google) <rostedt@goodmis.org> |
tracing: Add back FORTIFY_SOURCE logic to kernel_stack event structure
For backward compatibility, older tooling expects to see the kernel_stack event with a "caller" field that is a fixed size arra
tracing: Add back FORTIFY_SOURCE logic to kernel_stack event structure
For backward compatibility, older tooling expects to see the kernel_stack event with a "caller" field that is a fixed size array of 8 addresses. The code now supports more than 8 with an added "size" field that states the real number of entries. But the "caller" field still just looks like a fixed size to user space.
Since the tracing macros that create the user space format files also creates the structures that those files represent, the kernel_stack event structure had its "caller" field a fixed size of 8, but in reality, when it is allocated on the ring buffer, it can hold more if the stack trace is bigger that 8 functions. The copying of these entries was simply done with a memcpy():
size = nr_entries * sizeof(unsigned long); memcpy(entry->caller, fstack->calls, size);
The FORTIFY_SOURCE logic noticed at runtime that when the nr_entries was larger than 8, that the memcpy() was writing more than what the structure stated it can hold and it complained about it. This is because the FORTIFY_SOURCE code is unaware that the amount allocated is actually enough to hold the size. It does not expect that a fixed size field will hold more than the fixed size.
This was originally solved by hiding the caller assignment with some pointer arithmetic.
ptr = ring_buffer_data(); entry = ptr;
ptr += offsetof(typeof(*entry), caller); memcpy(ptr, fstack->calls, size);
But it is considered bad form to hide from kernel hardening. Instead, make it work nicely with FORTIFY_SOURCE by adding a new __stack_array() macro that is specific for this one special use case. The macro will take 4 arguments: type, item, len, field (whereas the __array() macro takes just the first three). This macro will act just like the __array() macro when creating the code to deal with the format file that is exposed to user space. But for the kernel, it will turn the caller field into:
type item[] __counted_by(field);
or for this instance:
unsigned long caller[] __counted_by(size);
Now the kernel code can expose the assignment of the caller to the FORTIFY_SOURCE and everyone is happy!
Link: https://lore.kernel.org/linux-trace-kernel/20230712105235.5fc441aa@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20230713092605.2ddb9788@rorschach.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by: Kees Cook <keescook@chromium.org>
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61b73694 |
| 24-Jul-2023 |
Thomas Zimmermann <tzimmermann@suse.de> |
Merge drm/drm-next into drm-misc-next
Backmerging to get v6.5-rc2.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
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0791faeb |
| 17-Jul-2023 |
Mark Brown <broonie@kernel.org> |
ASoC: Merge v6.5-rc2
Get a similar baseline to my other branches, and fixes for people using the branch.
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2f98e686 |
| 11-Jul-2023 |
Maxime Ripard <mripard@kernel.org> |
Merge v6.5-rc1 into drm-misc-fixes
Boris needs 6.5-rc1 in drm-misc-fixes to prevent a conflict.
Signed-off-by: Maxime Ripard <mripard@kernel.org>
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Revision tags: v6.1.38 |
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3fbff91a |
| 02-Jul-2023 |
Andrew Morton <akpm@linux-foundation.org> |
Merge branch 'master' into mm-hotfixes-stable
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Revision tags: v6.1.37 |
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cccf0c2e |
| 30-Jun-2023 |
Linus Torvalds <torvalds@linux-foundation.org> |
Merge tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Add new feature to have function graph tracer record the retur
Merge tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Add new feature to have function graph tracer record the return value. Adds a new option: funcgraph-retval ; when set, will show the return value of a function in the function graph tracer.
- Also add the option: funcgraph-retval-hex where if it is not set, and the return value is an error code, then it will return the decimal of the error code, otherwise it still reports the hex value.
- Add the file /sys/kernel/tracing/osnoise/per_cpu/cpu<cpu>/timerlat_fd That when a application opens it, it becomes the task that the timer lat tracer traces. The application can also read this file to find out how it's being interrupted.
- Add the file /sys/kernel/tracing/available_filter_functions_addrs that works just the same as available_filter_functions but also shows the addresses of the functions like kallsyms, except that it gives the address of where the fentry/mcount jump/nop is. This is used by BPF to make it easier to attach BPF programs to ftrace hooks.
- Replace strlcpy with strscpy in the tracing boot code.
* tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Fix warnings when building htmldocs for function graph retval riscv: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL tracing/boot: Replace strlcpy with strscpy tracing/timerlat: Add user-space interface tracing/osnoise: Skip running osnoise if all instances are off tracing/osnoise: Switch from PF_NO_SETAFFINITY to migrate_disable ftrace: Show all functions with addresses in available_filter_functions_addrs selftests/ftrace: Add funcgraph-retval test case LoongArch: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL x86/ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL arm64: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL tracing: Add documentation for funcgraph-retval and funcgraph-retval-hex function_graph: Support recording and printing the return value of function fgraph: Add declaration of "struct fgraph_ret_regs"
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Revision tags: v6.1.36, v6.4, v6.1.35, v6.1.34, v6.1.33, v6.1.32, v6.1.31, v6.1.30, v6.1.29, v6.1.28, v6.1.27, v6.1.26, v6.3, v6.1.25, v6.1.24 |
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a1be9ccc |
| 08-Apr-2023 |
Donglin Peng <pengdonglin@sangfor.com.cn> |
function_graph: Support recording and printing the return value of function
Analyzing system call failures with the function_graph tracer can be a time-consuming process, particularly when locating
function_graph: Support recording and printing the return value of function
Analyzing system call failures with the function_graph tracer can be a time-consuming process, particularly when locating the kernel function that first returns an error in the trace logs. This change aims to simplify the process by recording the function return value to the 'retval' member of 'ftrace_graph_ret' and printing it when outputting the trace log.
We have introduced new trace options: funcgraph-retval and funcgraph-retval-hex. The former controls whether to display the return value, while the latter controls the display format.
Please note that even if a function's return type is void, a return value will still be printed. You can simply ignore it.
This patch only establishes the fundamental infrastructure. Subsequent patches will make this feature available on some commonly used processor architectures.
Here is an example:
I attempted to attach the demo process to a cpu cgroup, but it failed:
echo `pidof demo` > /sys/fs/cgroup/cpu/test/tasks -bash: echo: write error: Invalid argument
The strace logs indicate that the write system call returned -EINVAL(-22): ... write(1, "273\n", 4) = -1 EINVAL (Invalid argument) ...
To capture trace logs during a write system call, use the following commands:
cd /sys/kernel/debug/tracing/ echo 0 > tracing_on echo > trace echo *sys_write > set_graph_function echo *spin* > set_graph_notrace echo *rcu* >> set_graph_notrace echo *alloc* >> set_graph_notrace echo preempt* >> set_graph_notrace echo kfree* >> set_graph_notrace echo $$ > set_ftrace_pid echo function_graph > current_tracer echo 1 > options/funcgraph-retval echo 0 > options/funcgraph-retval-hex echo 1 > tracing_on echo `pidof demo` > /sys/fs/cgroup/cpu/test/tasks echo 0 > tracing_on cat trace > ~/trace.log
To locate the root cause, search for error code -22 directly in the file trace.log and identify the first function that returned -22. Once you have identified this function, examine its code to determine the root cause.
For example, in the trace log below, cpu_cgroup_can_attach returned -22 first, so we can focus our analysis on this function to identify the root cause.
...
1) | cgroup_migrate() { 1) 0.651 us | cgroup_migrate_add_task(); /* = 0xffff93fcfd346c00 */ 1) | cgroup_migrate_execute() { 1) | cpu_cgroup_can_attach() { 1) | cgroup_taskset_first() { 1) 0.732 us | cgroup_taskset_next(); /* = 0xffff93fc8fb20000 */ 1) 1.232 us | } /* cgroup_taskset_first = 0xffff93fc8fb20000 */ 1) 0.380 us | sched_rt_can_attach(); /* = 0x0 */ 1) 2.335 us | } /* cpu_cgroup_can_attach = -22 */ 1) 4.369 us | } /* cgroup_migrate_execute = -22 */ 1) 7.143 us | } /* cgroup_migrate = -22 */
...
Link: https://lkml.kernel.org/r/1fc502712c981e0e6742185ba242992170ac9da8.1680954589.git.pengdonglin@sangfor.com.cn
Tested-by: Florian Kauer <florian.kauer@linutronix.de> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Revision tags: v6.1.23, v6.1.22, v6.1.21, v6.1.20, v6.1.19, v6.1.18, v6.1.17, v6.1.16, v6.1.15, v6.1.14, v6.1.13, v6.2, v6.1.12, v6.1.11, v6.1.10, v6.1.9, v6.1.8, v6.1.7, v6.1.6, v6.1.5, v6.0.19, v6.0.18, v6.1.4, v6.1.3, v6.0.17, v6.1.2, v6.0.16, v6.1.1, v6.0.15, v6.0.14, v6.0.13, v6.1, v6.0.12, v6.0.11, v6.0.10, v5.15.80, v6.0.9, v5.15.79, v6.0.8, v5.15.78, v6.0.7, v5.15.77, v5.15.76, v6.0.6, v6.0.5, v5.15.75, v6.0.4, v6.0.3, v6.0.2, v5.15.74, v5.15.73, v6.0.1, v5.15.72, v6.0, v5.15.71, v5.15.70, v5.15.69, v5.15.68, v5.15.67, v5.15.66, v5.15.65, v5.15.64, v5.15.63, v5.15.62, v5.15.61, v5.15.60, v5.15.59, v5.19, v5.15.58, v5.15.57, v5.15.56, v5.15.55, v5.15.54, v5.15.53, v5.15.52, v5.15.51, v5.15.50, v5.15.49, v5.15.48, v5.15.47, v5.15.46, v5.15.45, v5.15.44, v5.15.43, v5.15.42, v5.18, v5.15.41, v5.15.40, v5.15.39, v5.15.38, v5.15.37, v5.15.36, v5.15.35, v5.15.34, v5.15.33, v5.15.32, v5.15.31, v5.17, v5.15.30, v5.15.29, v5.15.28, v5.15.27, v5.15.26, v5.15.25, v5.15.24, v5.15.23, v5.15.22, v5.15.21, v5.15.20, v5.15.19, v5.15.18, v5.15.17, v5.4.173, v5.15.16, v5.15.15 |
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762f99f4 |
| 15-Jan-2022 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
Merge branch 'next' into for-linus
Prepare input updates for 5.17 merge window.
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Revision tags: v5.16, v5.15.10, v5.15.9, v5.15.8 |
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5d8dfaa7 |
| 09-Dec-2021 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
Merge tag 'v5.15' into next
Sync up with the mainline to get the latest APIs and DT bindings.
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Revision tags: v5.15.7, v5.15.6, v5.15.5, v5.15.4, v5.15.3, v5.15.2, v5.15.1, v5.15, v5.14.14, v5.14.13, v5.14.12, v5.14.11, v5.14.10, v5.14.9, v5.14.8, v5.14.7, v5.14.6, v5.10.67, v5.10.66, v5.14.5, v5.14.4, v5.10.65, v5.14.3, v5.10.64, v5.14.2, v5.10.63 |
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8be98d2f |
| 05-Sep-2021 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
Merge branch 'next' into for-linus
Prepare input updates for 5.15 merge window.
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Revision tags: v5.14.1, v5.10.62 |
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71af75b6 |
| 30-Aug-2021 |
Petr Mladek <pmladek@suse.com> |
Merge branch 'for-5.15-printk-index' into for-linus
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Revision tags: v5.14, v5.10.61 |
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46466ae3 |
| 26-Aug-2021 |
Ingo Molnar <mingo@kernel.org> |
Merge branch 'perf/urgent' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Revision tags: v5.10.60 |
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c87866ed |
| 17-Aug-2021 |
Ingo Molnar <mingo@kernel.org> |
Merge tag 'v5.14-rc6' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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ca31fef1 |
| 27-Jul-2021 |
Maarten Lankhorst <maarten.lankhorst@linux.intel.com> |
Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next
Required bump from v5.13-rc3 to v5.14-rc3, and to pick up sysfb compilation fixes.
Signed-off-by: Maarten Lankhorst <maarten.lankh
Backmerge remote-tracking branch 'drm/drm-next' into drm-misc-next
Required bump from v5.13-rc3 to v5.14-rc3, and to pick up sysfb compilation fixes.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
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353b7a55 |
| 27-Jul-2021 |
Tony Lindgren <tony@atomide.com> |
Merge branch 'fixes-v5.14' into fixes
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Revision tags: v5.10.53, v5.10.52, v5.10.51 |
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320424c7 |
| 18-Jul-2021 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
Merge tag 'v5.13' into next
Sync up with the mainline to get the latest parport API.
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Revision tags: v5.10.50 |
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611ac726 |
| 13-Jul-2021 |
Rodrigo Vivi <rodrigo.vivi@intel.com> |
Merge drm/drm-next into drm-intel-gt-next
Catching up with 5.14-rc1 and also preparing for a needed common topic branch for the "Minor revid/stepping and workaround cleanup"
Reference: https://patc
Merge drm/drm-next into drm-intel-gt-next
Catching up with 5.14-rc1 and also preparing for a needed common topic branch for the "Minor revid/stepping and workaround cleanup"
Reference: https://patchwork.freedesktop.org/series/92299/ Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
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d5bfbad2 |
| 13-Jul-2021 |
Rodrigo Vivi <rodrigo.vivi@intel.com> |
Merge drm/drm-next into drm-intel-next
Catching up with 5.14-rc1
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
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Revision tags: v5.10.49 |
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757fa80f |
| 03-Jul-2021 |
Linus Torvalds <torvalds@linux-foundation.org> |
Merge tag 'trace-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Added option for per CPU threads to the hwlat tracer
- Ha
Merge tag 'trace-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Added option for per CPU threads to the hwlat tracer
- Have hwlat tracer handle hotplug CPUs
- New tracer: osnoise, that detects latency caused by interrupts, softirqs and scheduling of other tasks.
- Added timerlat tracer that creates a thread and measures in detail what sources of latency it has for wake ups.
- Removed the "success" field of the sched_wakeup trace event. This has been hardcoded as "1" since 2015, no tooling should be looking at it now. If one exists, we can revert this commit, fix that tool and try to remove it again in the future.
- tgid mapping fixed to handle more than PID_MAX_DEFAULT pids/tgids.
- New boot command line option "tp_printk_stop", as tp_printk causes trace events to write to console. When user space starts, this can easily live lock the system. Having a boot option to stop just after boot up is useful to prevent that from happening.
- Have ftrace_dump_on_oops boot command line option take numbers that match the numbers shown in /proc/sys/kernel/ftrace_dump_on_oops.
- Bootconfig clean ups, fixes and enhancements.
- New ktest script that tests bootconfig options.
- Add tracepoint_probe_register_may_exist() to register a tracepoint without triggering a WARN*() if it already exists. BPF has a path from user space that can do this. All other paths are considered a bug.
- Small clean ups and fixes
* tag 'trace-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (49 commits) tracing: Resize tgid_map to pid_max, not PID_MAX_DEFAULT tracing: Simplify & fix saved_tgids logic treewide: Add missing semicolons to __assign_str uses tracing: Change variable type as bool for clean-up trace/timerlat: Fix indentation on timerlat_main() trace/osnoise: Make 'noise' variable s64 in run_osnoise() tracepoint: Add tracepoint_probe_register_may_exist() for BPF tracing tracing: Fix spelling in osnoise tracer "interferences" -> "interference" Documentation: Fix a typo on trace/osnoise-tracer trace/osnoise: Fix return value on osnoise_init_hotplug_support trace/osnoise: Make interval u64 on osnoise_main trace/osnoise: Fix 'no previous prototype' warnings tracing: Have osnoise_main() add a quiescent state for task rcu seq_buf: Make trace_seq_putmem_hex() support data longer than 8 seq_buf: Fix overflow in seq_buf_putmem_hex() trace/osnoise: Support hotplug operations trace/hwlat: Support hotplug operations trace/hwlat: Protect kdata->kthread with get/put_online_cpus trace: Add timerlat tracer trace: Add osnoise tracer ...
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5a94296b |
| 30-Jun-2021 |
Jiri Kosina <jkosina@suse.cz> |
Merge branch 'for-5.14/amd-sfh' into for-linus
- support for Renoir and Cezanne SoCs - support for Ambient Light Sensor - support for Human Presence Detection sensor
all from Basavaraj Natikar
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Revision tags: v5.13, v5.10.46 |
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a955d7ea |
| 22-Jun-2021 |
Daniel Bristot de Oliveira <bristot@redhat.com> |
trace: Add timerlat tracer
The timerlat tracer aims to help the preemptive kernel developers to found souces of wakeup latencies of real-time threads. Like cyclictest, the tracer sets a periodic tim
trace: Add timerlat tracer
The timerlat tracer aims to help the preemptive kernel developers to found souces of wakeup latencies of real-time threads. Like cyclictest, the tracer sets a periodic timer that wakes up a thread. The thread then computes a *wakeup latency* value as the difference between the *current time* and the *absolute time* that the timer was set to expire. The main goal of timerlat is tracing in such a way to help kernel developers.
Usage
Write the ASCII text "timerlat" into the current_tracer file of the tracing system (generally mounted at /sys/kernel/tracing).
For example:
[root@f32 ~]# cd /sys/kernel/tracing/ [root@f32 tracing]# echo timerlat > current_tracer
It is possible to follow the trace by reading the trace trace file:
[root@f32 tracing]# cat trace # tracer: timerlat # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # || / # |||| ACTIVATION # TASK-PID CPU# |||| TIMESTAMP ID CONTEXT LATENCY # | | | |||| | | | | <idle>-0 [000] d.h1 54.029328: #1 context irq timer_latency 932 ns <...>-867 [000] .... 54.029339: #1 context thread timer_latency 11700 ns <idle>-0 [001] dNh1 54.029346: #1 context irq timer_latency 2833 ns <...>-868 [001] .... 54.029353: #1 context thread timer_latency 9820 ns <idle>-0 [000] d.h1 54.030328: #2 context irq timer_latency 769 ns <...>-867 [000] .... 54.030330: #2 context thread timer_latency 3070 ns <idle>-0 [001] d.h1 54.030344: #2 context irq timer_latency 935 ns <...>-868 [001] .... 54.030347: #2 context thread timer_latency 4351 ns
The tracer creates a per-cpu kernel thread with real-time priority that prints two lines at every activation. The first is the *timer latency* observed at the *hardirq* context before the activation of the thread. The second is the *timer latency* observed by the thread, which is the same level that cyclictest reports. The ACTIVATION ID field serves to relate the *irq* execution to its respective *thread* execution.
The irq/thread splitting is important to clarify at which context the unexpected high value is coming from. The *irq* context can be delayed by hardware related actions, such as SMIs, NMIs, IRQs or by a thread masking interrupts. Once the timer happens, the delay can also be influenced by blocking caused by threads. For example, by postponing the scheduler execution via preempt_disable(), by the scheduler execution, or by masking interrupts. Threads can also be delayed by the interference from other threads and IRQs.
The timerlat can also take advantage of the osnoise: traceevents. For example:
[root@f32 ~]# cd /sys/kernel/tracing/ [root@f32 tracing]# echo timerlat > current_tracer [root@f32 tracing]# echo osnoise > set_event [root@f32 tracing]# echo 25 > osnoise/stop_tracing_total_us [root@f32 tracing]# tail -10 trace cc1-87882 [005] d..h... 548.771078: #402268 context irq timer_latency 1585 ns cc1-87882 [005] dNLh1.. 548.771082: irq_noise: local_timer:236 start 548.771077442 duration 4597 ns cc1-87882 [005] dNLh2.. 548.771083: irq_noise: reschedule:253 start 548.771083017 duration 56 ns cc1-87882 [005] dNLh2.. 548.771086: irq_noise: call_function_single:251 start 548.771083811 duration 2048 ns cc1-87882 [005] dNLh2.. 548.771088: irq_noise: call_function_single:251 start 548.771086814 duration 1495 ns cc1-87882 [005] dNLh2.. 548.771091: irq_noise: call_function_single:251 start 548.771089194 duration 1558 ns cc1-87882 [005] dNLh2.. 548.771094: irq_noise: call_function_single:251 start 548.771091719 duration 1932 ns cc1-87882 [005] dNLh2.. 548.771096: irq_noise: call_function_single:251 start 548.771094696 duration 1050 ns cc1-87882 [005] d...3.. 548.771101: thread_noise: cc1:87882 start 548.771078243 duration 10909 ns timerlat/5-1035 [005] ....... 548.771103: #402268 context thread timer_latency 25960 ns
For further information see: Documentation/trace/timerlat-tracer.rst
Link: https://lkml.kernel.org/r/71f18efc013e1194bcaea1e54db957de2b19ba62.1624372313.git.bristot@redhat.com
Cc: Phil Auld <pauld@redhat.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Kate Carcia <kcarcia@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alexandre Chartre <alexandre.chartre@oracle.com> Cc: Clark Willaims <williams@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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