[v4,00/29] Add trace file compression

Message

Tzvetomir Stoyanov (VMware) May 20, 2021, 3:19 a.m. UTC

A new PoC implementation, adding a compression to trace file.
A basic infrastructure for compression support is added into the trace-cmd
library. The zlib is used for compression, but more libraries and algorithms
can be added. Trace data is commpressed and part of the trace file metadata: 
 - ftrace events format
 - format of recorded events
 - information about the mapping of function addresses to the function names
 - trace_printk() format strings
 - information of the mapping a PID to a process name
 - options

Note: not all trace-cmd commands are tested with these changes. These are
verified to work with compressed trace files:
 trace-cmd record
 trace-cmd report
 trace-cmd dump
 trace-cmd agent
 trace-cmd profile
 trace-cmd split

Todo list, in order to have complete trace file compression:
 - Add support for more compression libraries.
 - Add new trace-cmd command to convert trace files from version 6 to
   version 7 and vise versa.
 - Test all trace-cmd commands with trace file v7.
 - Update trace-cmd documentation.

v4 changes:
 - Tested and fixed profile and split subcommands with compression files.
 - Bug fixes.

v3 changes:
 - Compress the trace data.
 - Added documentation to all compression APIs.
 - A few minor fixes.
v2 changes:
 - Refactored compression APIs.
 - Moved the trace buffers description out of the trace options section.
 - Added compression of "options" section of the trace file.
 - Updated "trace-cmd list" to show available compression algorithms.
 - Tested with host-guest tracing.
 - Merged with the patchset that bumps the trace file version.

Tzvetomir Stoyanov (VMware) (29):
  trace-cmd library: Remove unused private APIs for creating trace files
  trace-cmd library: Remove unused API tracecmd_update_option
  trace-cmd: Check if file version is supported
  trace-cmd library: Add new API to get file version of input handler
  trace-cmd library: Select the file version when writing trace file
  trace-cmd: Add APIs for library initialization and free
  trace-cmd library: Add support for compression algorithms
  trace-cmd list: Show supported compression algorithms
  trace-cmd library: Bump the trace file version to 7
  trace-cmd library: Compress part of the trace file
  trace-cmd library: Read compressed trace file
  trace-cmd library: Add new API to get compression of input handler
  trace-cmd library: Inherit compression algorithm from input file
  trace-cmd library: Extend the create file APIs to support different
    compression
  trace-cmd record: Add new parameter --compression
  trace-cmd dump: Add support for trace files version 7
  trace-cmd library: Add support for zlib compression library
  trace-cmd library: Hide the logic for updating buffer offset
  trace-cmd: Move buffers description outside of options
  trace-cmd library: Track the offset in the option section in the trace
    file
  trace-cmd library: Add compression of the option section of the trace
    file
  trace-cmd library: Refactor the logic for writing trace data in the
    file
  trace-cmd library: Add APIs for read and write compressed data in
    chunks
  trace-cmd: Compress trace data
  trace-cmd: Read compressed trace data
  trace-cmd library: Reuse within the library the function that checks
    file state.
  trace-cmd library: New internal API to set file state of output
    handler
  trace-cmd library: Make tracecmd_copy_headers() to work with output
    handler
  trace-cmd: Do not use trace file compression with streams

 lib/trace-cmd/Makefile                        |  11 +
 .../include/private/trace-cmd-private.h       |  79 +-
 lib/trace-cmd/include/trace-cmd-local.h       |  25 +-
 lib/trace-cmd/trace-compress-zlib.c           | 172 ++++
 lib/trace-cmd/trace-compress.c                | 787 ++++++++++++++++++
 lib/trace-cmd/trace-input.c                   | 711 +++++++++++-----
 lib/trace-cmd/trace-output.c                  | 738 ++++++++++------
 lib/trace-cmd/trace-util.c                    |  60 ++
 tracecmd/trace-cmd.c                          |  11 +-
 tracecmd/trace-dump.c                         | 162 +++-
 tracecmd/trace-list.c                         |  26 +
 tracecmd/trace-listen.c                       |   3 +
 tracecmd/trace-read.c                         |   8 +
 tracecmd/trace-record.c                       |  42 +-
 tracecmd/trace-restore.c                      |   4 +-
 tracecmd/trace-stream.c                       |   2 +-
 tracecmd/trace-usage.c                        |   6 +
 17 files changed, 2342 insertions(+), 505 deletions(-)
 create mode 100644 lib/trace-cmd/trace-compress-zlib.c
 create mode 100644 lib/trace-cmd/trace-compress.c