mirror of
https://github.com/torvalds/linux.git
synced 2026-07-29 10:41:49 +02:00
Linux kernel source tree
f692a6c690
- Fix a regression in the irqsoff and wakeup latency tracing The function graph tracer infrastructure has become generic so that fprobes and BPF can be based on it. As it use to only handle function graph tracing, it would always calculate the time the function entered so that it could then calculate the time it exits and give the length of time the function executed for. But this is not needed for the other users (fprobes and BPF) and reading the clock adds a non-negligible overhead, so the calculation was moved into the function graph tracer logic. But the irqsoff and wakeup latency tracers, when the "display-graph" option was set, would use the function graph tracer to calculate the times of functions during the latency. The movement of the calltime calculation made the value zero for these tracers, and the output no longer showed the length of time of each tracer, but instead the absolute timestamp of when the function returned (rettime - calltime where calltime is now zero). Have the irqsoff and wakeup latency tracers also do the calltime calculation as the function graph tracer does and report the proper length of the function timings. - Update the tracing display to reflect the new preempt lazy model When the system is configured with preempt lazy, the output of the trace data would state "unknown" for the current preemption model. Because the lazy preemption model was just added, make it known to the tracing subsystem too. This is just a one line change. - Document multiple function graph having slightly different timings Now that function graph tracer infrastructure is separate, this also allows the function graph tracer to run in multiple instances (it wasn't able to do so before). If two instances ran the function graph tracer and traced the same functions, the timings for them will be slightly different because each does their own timings and collects the timestamps differently. Document this to not have people be confused by it. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ4kcvhQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qnaPAPwPrZraRcXCF2SvWfF6aJ/hSVzy7XgM mj7FDlkw57QlVgD/cy/g8czLQ38hAqNULP+tvPc6mPSHptV8yOTKaWuVFgg= =N7/a -----END PGP SIGNATURE----- Merge tag 'trace-v6.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix a regression in the irqsoff and wakeup latency tracing The function graph tracer infrastructure has become generic so that fprobes and BPF can be based on it. As it use to only handle function graph tracing, it would always calculate the time the function entered so that it could then calculate the time it exits and give the length of time the function executed for. But this is not needed for the other users (fprobes and BPF) and reading the clock adds a non-negligible overhead, so the calculation was moved into the function graph tracer logic. But the irqsoff and wakeup latency tracers, when the "display-graph" option was set, would use the function graph tracer to calculate the times of functions during the latency. The movement of the calltime calculation made the value zero for these tracers, and the output no longer showed the length of time of each tracer, but instead the absolute timestamp of when the function returned (rettime - calltime where calltime is now zero). Have the irqsoff and wakeup latency tracers also do the calltime calculation as the function graph tracer does and report the proper length of the function timings. - Update the tracing display to reflect the new preempt lazy model When the system is configured with preempt lazy, the output of the trace data would state "unknown" for the current preemption model. Because the lazy preemption model was just added, make it known to the tracing subsystem too. This is just a one line change. - Document multiple function graph having slightly different timings Now that function graph tracer infrastructure is separate, this also allows the function graph tracer to run in multiple instances (it wasn't able to do so before). If two instances ran the function graph tracer and traced the same functions, the timings for them will be slightly different because each does their own timings and collects the timestamps differently. Document this to not have people be confused by it. * tag 'trace-v6.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ftrace: Document that multiple function_graph tracing may have different times tracing: Print lazy preemption model tracing: Fix irqsoff and wakeup latency tracers when using function graph |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.