Add support to align ftrace and LTTng US trace #3
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
By separating the plugin registration part from the implementation part, we prepare the codebase for adding further components. Signed-off-by: Felix Moessbauer <[email protected]>
The log helper depends on stdio.h. This remained unnoticed, as all downstream users have this header included anyways. Signed-off-by: Felix Moessbauer <[email protected]>
We need to be able to recreate the clock definiton of another trace to ensure clocks that are equal are actually detected as equal by the muxer. Otherwise the traces which are related cannot be muxed. Signed-off-by: Felix Moessbauer <[email protected]>
fmoessbauer
force-pushed
the
fm/clock-offset
branch
2 times, most recently
from
c4cc9fe to
7effe03
Compare
As a preparation to align the ftrace trace and the LTTng US trace, we need a way to gather information about the clock used in the LTTng US trace (stream). To avoid the parsing of the CTF metadata, we add a sink that extracts the relevant clock definitions from the stream beginning messages and emits them as JSON lines on a file descriptor. Signed-off-by: Felix Moessbauer <[email protected]>
We first acquire data about the clock of the LTTng US trace, which contains a reference point to the world clock. Then, we use that information to create the ftrace clock accordingly and finally mux the traces. By that, the aligned traces can directly be viewed in tracecompass without any further postprocessing. Signed-off-by: Felix Moessbauer <[email protected]>
These env options are parsed by downstream plugins (like the CTF sink) and define how the CTF files are layed out. We further introduce a auto-generated config file to inject our own tracer version if not overridden. Signed-off-by: Felix Moessbauer <[email protected]>
fmoessbauer
force-pushed
the
fm/clock-offset
branch
from
7effe03 to
1cd366a
Compare
The trace.dat file contains information that is important to map the kernel trace to a userland trace. However, the APIs to access this information is only exposed via exported symbols, but not officially part of the API. To deal with this until this has been clarified upstream, we add a build option to allow the usage of a limited set of private libtracecmd functions. Signed-off-by: Felix Moessbauer <[email protected]>
fmoessbauer
force-pushed
the
fm/clock-offset
branch
2 times, most recently
from
487e29f to
1aa1cf5
Compare
The sink.ctf.fs sink has logic that detects if a processed trace is an LTTng trace. If it is, the output directory is layed out as done by LTTng. To support this, we need to pass metadata from the LTTng US trace into the ftrace source. This is implemented in a two staged approach: Metadata we can read from the ftrace itself is just added. Metadata (like the trace-name) that is only available in the LTTng US trace is copied over. Signed-off-by: Felix Moessbauer <[email protected]>
fmoessbauer
force-pushed
the
fm/clock-offset
branch
from
1aa1cf5 to
175bec9
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
We first acquire data about the clock of the LTTng US trace, which contains a reference point to the world clock. Then, we use that information to create the ftrace clock accordingly and finally mux the traces.
By that, the aligned traces can directly be viewed in tracecompass without any further postprocessing.