docs: ftrace: always use canonical ftrace path

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

Before 4.1, all ftrace traci

docs: ftrace: always use canonical ftrace path

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:

/sys/kernel/debug/tracing

Many parts of Documentation still reference this older debugfs path, so
let's update them to avoid confusion.

Signed-off-by: Ross Zwisler <[email protected]>
Reviewed-by: Steven Rostedt (Google) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jonathan Corbet <[email protected]>

show more ...

tweewide: Fix most Shebang lines

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

tweewide: Fix most Shebang lines

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

Signed-off-by: Finn Behrens <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

show more ...

mm-tracepoint: rename page-free events

Rename mm_page_free_direct into mm_page_free and mm_pagevec_free into
mm_page_free_batched

Since v2.6.33-5426-gc475dab the kernel triggers mm_page_free_direct

mm-tracepoint: rename page-free events

Rename mm_page_free_direct into mm_page_free and mm_pagevec_free into
mm_page_free_batched

Since v2.6.33-5426-gc475dab the kernel triggers mm_page_free_direct for
all freed pages, not only for directly freed. So, let's name it properly.
For pages freed via page-list we also trigger mm_page_free_batched event.

Signed-off-by: Konstantin Khlebnikov <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Reviewed-by: Minchan Kim <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

tracing, page-allocator: add a postprocessing script for page-allocator-related ftrace events

This patch adds a simple post-processing script for the
page-allocator-related trace events. It can be

tracing, page-allocator: add a postprocessing script for page-allocator-related ftrace events

This patch adds a simple post-processing script for the
page-allocator-related trace events. It can be used to give an indication
of who the most allocator-intensive processes are and how often the zone
lock was taken during the tracing period. Example output looks like

Process Pages Pages Pages Pages PCPU PCPU PCPU Fragment Fragment MigType Fragment Fragment Unknown
details allocd allocd freed freed pages drains refills Fallback Causing Changed Severe Moderate
under lock direct pagevec drain
swapper-0 0 0 2 0 0 0 0 0 0 0 0 0 0
Xorg-3770 10603 5952 3685 6978 5996 194 192 0 0 0 0 0 0
modprobe-21397 51 0 0 86 31 1 0 0 0 0 0 0 0
xchat-5370 228 93 0 0 0 0 3 0 0 0 0 0 0
awesome-4317 32 32 0 0 0 0 32 0 0 0 0 0 0
thinkfan-3863 2 0 1 1 0 0 0 0 0 0 0 0 0
hald-addon-stor-3935 2 0 0 0 0 0 0 0 0 0 0 0 0
akregator-4506 1 1 0 0 0 0 1 0 0 0 0 0 0
xmms-14888 0 0 1 0 0 0 0 0 0 0 0 0 0
khelper-12 1 0 0 0 0 0 0 0 0 0 0 0 0

Optionally, the output can include information on the parent or aggregate
based on process name instead of aggregating based on each pid. Example output
including parent information and stripped out the PID looks something like;

Process Pages Pages Pages Pages PCPU PCPU PCPU Fragment Fragment MigType Fragment Fragment Unknown
details allocd allocd freed freed pages drains refills Fallback Causing Changed Severe Moderate
under lock direct pagevec drain
gdm-3756 :: Xorg-3770 3796 2976 99 3813 3224 104 98 0 0 0 0 0 0
init-1 :: hald-3892 1 0 0 0 0 0 0 0 0 0 0 0 0
git-21447 :: editor-21448 4 0 4 0 0 0 0 0 0 0 0 0 0

This says that Xorg allocated 3796 pages and it's parent process is gdm
with a PID of 3756;

The postprocessor parses the text output of tracing. While there is a
binary format, the expectation is that the binary output can be readily
translated into text and post-processed offline. Obviously if the text
format changes, the parser will break but the regular expression parser is
fairly rudimentary so should be readily adjustable.

Signed-off-by: Mel Gorman <[email protected]>
Cc: Rik van Riel <[email protected]>
Reviewed-by: Ingo Molnar <[email protected]>
Cc: Larry Woodman <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Li Ming Chun <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...