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ecd4960d90
If no target is specified for 'latency' subcommand, the execution fails
because - 1 (invalid value) is written to set_ftrace_pid tracefs file.
Make system wide the default target, which is the same as the default
behavior of 'trace' subcommand.
Before the fix:
# perf ftrace latency -T schedule
failed to set ftrace pid
After the fix:
# perf ftrace latency -T schedule
^C# DURATION | COUNT | GRAPH |
0 - 1 us | 0 | |
1 - 2 us | 0 | |
2 - 4 us | 0 | |
4 - 8 us | 2828 | #### |
8 - 16 us | 23953 | ######################################## |
16 - 32 us | 408 | |
32 - 64 us | 318 | |
64 - 128 us | 4 | |
128 - 256 us | 3 | |
256 - 512 us | 0 | |
512 - 1024 us | 1 | |
1 - 2 ms | 4 | |
2 - 4 ms | 0 | |
4 - 8 ms | 0 | |
8 - 16 ms | 0 | |
16 - 32 ms | 0 | |
32 - 64 ms | 0 | |
64 - 128 ms | 0 | |
128 - 256 ms | 4 | |
256 - 512 ms | 2 | |
512 - 1024 ms | 0 | |
1 - ... s | 0 | |
Fixes: 53be502822 ("perf ftrace: Add 'latency' subcommand")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230324032702.109964-1-yangjihong1@huawei.com
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
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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.