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416e15ad17
This is a preparation to add more sub-commands for ftrace. The
'trace' subcommand does the same thing when no subcommand is given.
Committer testing:
The previous mode, i.e. no subcommand and the new 'perf ftrace trace'
are equivalent:
# perf ftrace -G check_preempt_curr sleep 0.00001
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
25) | check_preempt_curr() {
25) | resched_curr() {
25) | native_smp_send_reschedule() {
25) | default_send_IPI_single_phys() {
25) 0.110 us | __default_send_IPI_dest_field();
25) 0.490 us | }
25) 0.640 us | }
25) 0.850 us | }
25) 2.060 us | }
# perf ftrace trace -G check_preempt_curr sleep 0.00001
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
10) | check_preempt_curr() {
10) | resched_curr() {
10) | native_smp_send_reschedule() {
10) | default_send_IPI_single_phys() {
10) 0.080 us | __default_send_IPI_dest_field();
10) 0.460 us | }
10) 0.610 us | }
10) 0.830 us | }
10) 2.020 us | }
#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Changbin Du <changbin.du@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20211215185154.360314-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 Restructured Text 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.