Commit Graph

6 Commits

Author SHA1 Message Date
Dean Michael Berris b81372b56b [XRay][compiler-rt] Cleanup some internal XRay utilities
This change uses 'const' for the retryingWriteAll(...) API and removes
unnecessary 'static' local variables in getting the temporary filename.

llvm-svn: 334267
2018-06-08 07:48:03 +00:00
Tim Shen 7d0bffb537 [XRay] Refactor TSC related functions into a single header. NFC.
Summary:
The implementation, however, is in different arch-specific files, unless it's emulated.

Reviewers: dberris, pelikan, javed.absar

Subscribers: aemerson, llvm-commits

Differential Revision: https://reviews.llvm.org/D29796

llvm-svn: 294777
2017-02-10 20:30:43 +00:00
Dean Michael Berris ea9042cf8f [XRay][compiler-rt][NFC] Turn ProudCase functions to humbleCase functions
Summary:
As pointed out in casual reading of the XRay codebase, that we had
some interesting named functions that didn't quite follow the LLVM coding
conventions.

Reviewers: chandlerc, dblaikie

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29625

llvm-svn: 294373
2017-02-07 23:35:34 +00:00
Dean Michael Berris e7dbebf182 [XRay][compiler-rt] XRay Flight Data Recorder Mode
Summary:
In this change we introduce the notion of a "flight data recorder" mode
for XRay logging, where XRay logs in-memory first, and write out data
on-demand as required (as opposed to the naive implementation that keeps
logging while tracing is "on"). This depends on D26232 where we
implement the core data structure for holding the buffers that threads
will be using to write out records of operation.

This implementation only currently works on x86_64 and depends heavily
on the TSC math to write out smaller records to the inmemory buffers.

Also, this implementation defines two different kinds of records with
different sizes (compared to the current naive implementation): a
MetadataRecord (16 bytes) and a FunctionRecord (8 bytes). MetadataRecord
entries are meant to write out information like the thread ID for which
the metadata record is defined for, whether the execution of a thread
moved to a different CPU, etc. while a FunctionRecord represents the
different kinds of function call entry/exit records we might encounter
in the course of a thread's execution along with a delta from the last
time the logging handler was called.

While this implementation is not exactly what is described in the
original XRay whitepaper, this one gives us an initial implementation
that we can iterate and build upon.

Reviewers: echristo, rSerge, majnemer

Subscribers: mehdi_amini, llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D27038

llvm-svn: 293015
2017-01-25 03:50:46 +00:00
Dean Michael Berris 0aba35710f Revert "[XRay][compiler-rt] XRay Flight Data Recorder Mode"
This reverts rL290852 as it breaks aarch64 and arm.

llvm-svn: 290854
2017-01-03 04:04:00 +00:00
Dean Michael Berris 33d305b54b [XRay][compiler-rt] XRay Flight Data Recorder Mode
Summary:
In this change we introduce the notion of a "flight data recorder" mode
for XRay logging, where XRay logs in-memory first, and write out data
on-demand as required (as opposed to the naive implementation that keeps
logging while tracing is "on"). This depends on D26232 where we
implement the core data structure for holding the buffers that threads
will be using to write out records of operation.

This implementation only currently works on x86_64 and depends heavily
on the TSC math to write out smaller records to the inmemory buffers.

Also, this implementation defines two different kinds of records with
different sizes (compared to the current naive implementation): a
MetadataRecord (16 bytes) and a FunctionRecord (8 bytes). MetadataRecord
entries are meant to write out information like the thread ID for which
the metadata record is defined for, whether the execution of a thread
moved to a different CPU, etc. while a FunctionRecord represents the
different kinds of function call entry/exit records we might encounter
in the course of a thread's execution along with a delta from the last
time the logging handler was called.

While this implementation is not exactly what is described in the
original XRay whitepaper, this one gives us an initial implementation
that we can iterate and build upon.

Reviewers: echristo, rSerge, majnemer

Subscribers: mehdi_amini, llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D27038

llvm-svn: 290852
2017-01-03 03:38:17 +00:00