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Previously inject->is_pipe was set if the input or output were a
pipe. Determining the input was a pipe had to be done prior to
starting the session and opening the file. This was done by comparing
the input file name with '-' but it fails if the pipe file is written
to disk.
Opening a pipe file from disk will correctly set perf_data.is_pipe, but
this is too late for 'perf inject' and results in a broken file. A
workaround is 'cat pipe_perf|perf inject -i - ...'.
This change removes inject->is_pipe and changes the dependent
conditions to use the is_pipe flag on the input
(inject->session->data) and output files (inject->output). This
ensures the is_pipe condition reflects things like the header being
read.
The change removes the use of perf file header repiping, that is
writing the file header out while reading it in. The case of input
pipe and output file cannot repipe as the attributes for the file are
unknown. To resolve this, write the file header when writing to disk
and as the attributes may be unknown, write them after the data.
Update sessions repipe variable to be trace_event_repipe as those are
the only events now impacted by it. Update __perf_session__new as the
repipe_fd no longer needs passing. Fully removing repipe from session
header reading will be done in a later change.
Committer testing:
root@number:~# perf record -e syscalls:sys_enter_*sleep/max-stack=4/ -o - sleep 0.01 | perf report -i -
# To display the perf.data header info, please use --header/--header-only options.
#
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.050 MB - ]
#
# Total Lost Samples: 0
#
# Samples: 1 of event 'syscalls:sys_enter_clock_nanosleep'
# Event count (approx.): 1
#
# Overhead Command Shared Object Symbol
# ........ ....... ............. ...............................
#
100.00% sleep libc.so.6 [.] clock_nanosleep@GLIBC_2.2.5
|
---__libc_start_main@@GLIBC_2.34
__libc_start_call_main
0x562fc2560a9f
clock_nanosleep@GLIBC_2.2.5
#
# (Tip: Create an archive with symtabs to analyse on other machine: perf archive)
#
root@number:~# perf record -e syscalls:sys_enter_*sleep/max-stack=4/ -o - sleep 0.01 > pipe.data
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.050 MB - ]
root@number:~# perf report --stdio -i pipe.data
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 1 of event 'syscalls:sys_enter_clock_nanosleep'
# Event count (approx.): 1
#
# Overhead Command Shared Object Symbol
# ........ ....... ............. ...............................
#
100.00% sleep libc.so.6 [.] clock_nanosleep@GLIBC_2.2.5
|
---__libc_start_main@@GLIBC_2.34
__libc_start_call_main
0x55f775975a9f
clock_nanosleep@GLIBC_2.2.5
#
# (Tip: To set sampling period of individual events use perf record -e cpu/cpu-cycles,period=100001/,cpu/branches,period=10001/ ...)
#
root@number:~#
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240829150154.37929-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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 reStructuredText 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.