diff options
| author | Keith Wyss <wyssman@gmail.com> | 2017-10-19 22:35:09 +0000 |
|---|---|---|
| committer | Keith Wyss <wyssman@gmail.com> | 2017-10-19 22:35:09 +0000 |
| commit | 4dea1f2710d56ea01dc941d932a3dafb86ea96f3 (patch) | |
| tree | 0ac8a245e735e8dcbc6aebb9e1f81f3141d3fab7 /docs/XRay.rst | |
| parent | 5ce470a389c4bd24c1fd6d6db25cbb52205e0754 (diff) | |
[XRay] [docs] Document how to generate flamegraphs from xray traces.
Summary:
Updated the XRayExample docs with instructions for using the llvm-xray stacks
command.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39106
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316192 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/XRay.rst')
| -rw-r--r-- | docs/XRay.rst | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/docs/XRay.rst b/docs/XRay.rst index 3009c8794a2..9e08c358803 100644 --- a/docs/XRay.rst +++ b/docs/XRay.rst @@ -262,6 +262,8 @@ supports the following subcommands: only converts to YAML. - ``graph``: Generates a DOT graph of the function call relationships between functions found in an XRay trace. +- ``stack``: Reconstructs function call stacks from a timeline of function + calls in an XRay trace. These subcommands use various library components found as part of the XRay libraries, distributed with the LLVM distribution. These are: @@ -274,7 +276,7 @@ libraries, distributed with the LLVM distribution. These are: associated with edges and vertices. - ``llvm/XRay/InstrumentationMap.h``: A convenient tool for analyzing the instrumentation map in XRay-instrumented object files and binaries. The - ``extract`` subcommand uses this particular library. + ``extract`` and ``stack`` subcommands uses this particular library. Future Work =========== @@ -282,13 +284,17 @@ Future Work There are a number of ongoing efforts for expanding the toolset building around the XRay instrumentation system. -Trace Analysis --------------- - -We have more subcommands and modes that we're thinking of developing, in the -following forms: +Trace Analysis Tools +-------------------- -- ``stack``: Reconstruct the function call stacks in a timeline. +- Work is in progress to integrate with or develop tools to visualize findings + from an XRay trace. Particularly, the ``stack`` tool is being expanded to + output formats that allow graphing and exploring the duration of time in each + call stack. +- With a large instrumented binary, the size of generated XRay traces can + quickly become unwieldy. We are working on integrating pruning techniques and + heuristics for the analysis tools to sift through the traces and surface only + relevant information. More Platforms -------------- |