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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-02-22 12:00:20 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-02-22 12:00:20 -0800 |
commit | 70756b49be4ea8bf36a664322df6e7e89895fa60 (patch) | |
tree | fdbbf14342cf0124e08665e144678ccbbda6a1dc /Documentation/trace/mmiotrace.rst | |
parent | bc009f9382bd0704273c9a0c1cbf72020bbbe1f7 (diff) | |
parent | cc29eadef921fe52aa58f32536a93d9ea0ca3eb7 (diff) | |
download | lwn-70756b49be4ea8bf36a664322df6e7e89895fa60.tar.gz lwn-70756b49be4ea8bf36a664322df6e7e89895fa60.zip |
Merge tag 'docs-6.3' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"It has been a moderately calm cycle for documentation; the significant
changes include:
- Some significant additions to the memory-management documentation
- Some improvements to navigation in the HTML-rendered docs
- More Spanish and Chinese translations
... and the usual set of typo fixes and such"
* tag 'docs-6.3' of git://git.lwn.net/linux: (68 commits)
Documentation/watchdog/hpwdt: Fix Format
Documentation/watchdog/hpwdt: Fix Reference
Documentation: core-api: padata: correct spelling
docs/mm: Physical Memory: correct spelling in reference to CONFIG_PAGE_EXTENSION
docs: Use HTML comments for the kernel-toc SPDX line
docs: Add more information to the HTML sidebar
Documentation: KVM: Update AMD memory encryption link
printk: Document that CONFIG_BOOT_PRINTK_DELAY required for boot_delay=
Documentation: userspace-api: correct spelling
Documentation: sparc: correct spelling
Documentation: driver-api: correct spelling
Documentation: admin-guide: correct spelling
docs: add workload-tracing document to admin-guide
docs/admin-guide/mm: remove useless markup
docs/mm: remove useless markup
docs/mm: Physical Memory: remove useless markup
docs/sp_SP: Add process magic-number translation
docs: ftrace: always use canonical ftrace path
Doc/damon: fix the data path error
dma-buf: Add "dma-buf" to title of documentation
...
Diffstat (limited to 'Documentation/trace/mmiotrace.rst')
-rw-r--r-- | Documentation/trace/mmiotrace.rst | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/Documentation/trace/mmiotrace.rst b/Documentation/trace/mmiotrace.rst index fed13eaead89..95b750722a13 100644 --- a/Documentation/trace/mmiotrace.rst +++ b/Documentation/trace/mmiotrace.rst @@ -36,11 +36,11 @@ Usage Quick Reference :: $ mount -t debugfs debugfs /sys/kernel/debug - $ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer - $ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt & + $ echo mmiotrace > /sys/kernel/tracing/current_tracer + $ cat /sys/kernel/tracing/trace_pipe > mydump.txt & Start X or whatever. - $ echo "X is up" > /sys/kernel/debug/tracing/trace_marker - $ echo nop > /sys/kernel/debug/tracing/current_tracer + $ echo "X is up" > /sys/kernel/tracing/trace_marker + $ echo nop > /sys/kernel/tracing/current_tracer Check for lost events. @@ -56,11 +56,11 @@ Check that the driver you are about to trace is not loaded. Activate mmiotrace (requires root privileges):: - $ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer + $ echo mmiotrace > /sys/kernel/tracing/current_tracer Start storing the trace:: - $ cat /sys/kernel/debug/tracing/trace_pipe > mydump.txt & + $ cat /sys/kernel/tracing/trace_pipe > mydump.txt & The 'cat' process should stay running (sleeping) in the background. @@ -68,14 +68,14 @@ Load the driver you want to trace and use it. Mmiotrace will only catch MMIO accesses to areas that are ioremapped while mmiotrace is active. During tracing you can place comments (markers) into the trace by -$ echo "X is up" > /sys/kernel/debug/tracing/trace_marker +$ echo "X is up" > /sys/kernel/tracing/trace_marker This makes it easier to see which part of the (huge) trace corresponds to which action. It is recommended to place descriptive markers about what you do. Shut down mmiotrace (requires root privileges):: - $ echo nop > /sys/kernel/debug/tracing/current_tracer + $ echo nop > /sys/kernel/tracing/current_tracer The 'cat' process exits. If it does not, kill it by issuing 'fg' command and pressing ctrl+c. @@ -93,12 +93,12 @@ events were lost, the trace is incomplete. You should enlarge the buffers and try again. Buffers are enlarged by first seeing how large the current buffers are:: - $ cat /sys/kernel/debug/tracing/buffer_size_kb + $ cat /sys/kernel/tracing/buffer_size_kb gives you a number. Approximately double this number and write it back, for instance:: - $ echo 128000 > /sys/kernel/debug/tracing/buffer_size_kb + $ echo 128000 > /sys/kernel/tracing/buffer_size_kb Then start again from the top. |