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authorLinus Torvalds <torvalds@linux-foundation.org>2023-02-22 12:00:20 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2023-02-22 12:00:20 -0800
commit70756b49be4ea8bf36a664322df6e7e89895fa60 (patch)
treefdbbf14342cf0124e08665e144678ccbbda6a1dc /Documentation/trace/mmiotrace.rst
parentbc009f9382bd0704273c9a0c1cbf72020bbbe1f7 (diff)
parentcc29eadef921fe52aa58f32536a93d9ea0ca3eb7 (diff)
downloadlwn-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.rst20
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.