Displaying 20 results from an estimated 2000 matches similar to: "XRay Trace of Clang, Loadable through Chrome Trace Viewer"
2017 Dec 05
2
[cfe-dev] XRay Trace of Clang, Loadable through Chrome Trace Viewer
Sent from my iPhone
> On 6 Dec 2017, at 4:17 am, Brian Cain <brian.cain at gmail.com> wrote:
>
>
>
>> On Tue, Dec 5, 2017 at 9:49 AM, Dean Michael Berris via cfe-dev <cfe-dev at lists.llvm.org> wrote:
>> Hi cfe-dev@ and llvm-dev@,
>>
>> I've attached a Chrome trace-viewer readable trace of a clang built with XRay instrumentation (additional
2018 Mar 11
1
Using Xray compilation with C programs
Hi all,
I was interested in trying out the Xray profiling component in LLVM and was
trying to compile a C program with Clang with Xray flags. Unfortunately, I
keep getting a linker error everytime I try to compile the C program with
Clang. However, the error goes away when I try to compile the same C
program with Clang++ with -xc++ flag.
Searching around for this issue, looks like somebody has
2016 Jul 20
2
[XRay] Build instrumented Clang, some analysis results
Hi everyone,
TL;DR: With current pending patches applied in compiler-rt and llvm, and trunk clang, you can build your application with XRay tracing enabled on Linux with tracing enabled before main starts, and logging stops when the main thread exits.
Just a quick update, I have some patches under review that when applied cleanly to LLVM and compiler-rt allows for building applications with XRay
2019 Jan 21
2
[X-ray] How to check successful instrumentation and generate call trace?
Hi all,
I want to test X-ray performance and compare it with other research tools, so I use Clang 7.0.0 to compile and instrument GNU binutils-2.3.1 with the following commands:
cd binutils-2.31/
mkdir build
cd build/
CC=$local/clang CXX=$local/clang++ CFLAGS=-fxray-instrument CXXFLAGS=-fxray-instrument ../configure --prefix=/home/zhangysh1995/local
make
Then I extract instrumentation map
2019 Feb 02
2
[llvm-xray] llvm-xray cannot log every functions
Hi there,
I have a problem using the function call tracing tools that is designed in llvm tools set. My aim is to record every function call that a program makes when it run. However, for whatever reason, a simple matrix multiply c program that I wrote cannot record all the function calls that happened when the program run.
Here is the program: matrix.c
#include <stdio.h>
void
2017 Jun 08
2
XRay threshold (bug?)
Hi Dean,
I've noticed that XRay in llvm\lib\CodeGen\XRayInstrumentation.cpp compares
its threshold against Function::size() . However, Function::size() returns
the number of basic blocks (as I understand, such as cycle bodies, if/else
bodies, switch-case bodies, etc.), rather than the number of instructions.
Was your intent to count the instructions instead? The name of the
parameter
2018 Aug 27
2
Testing LLVM XRay
Hi All,
I am trying to test run clang XRay tool. I was following the steps at [1].
But the log file does not seem to get generated. According to the
instructions I used 'fxray-instrument' switch when compiling and then
specified 'patch_premain=true' at XRAY_OPTIONS. Is there anything else that
I need to do? I am on a trunk build of clang. Could that be it? I am on
clang version
2016 Jun 28
2
XRay: Demo on x86_64/Linux almost done; some questions.
Hi,
The following three patches, when applied cleanly to LLVM+Clang+compiler-rt
will now allow for building and running binaries with a very simple version
of XRay included:
http://reviews.llvm.org/D21612 (compiler-rt)
http://reviews.llvm.org/D20352 (clang)
http://reviews.llvm.org/D19904 (llvm)
To use this on x86_64-unknown-linux-gnu you'd need to set the flags
'-fxray-instrument'
2016 Jun 22
2
x86: How to Force 2-byte `jmp` instruction in lowering
Thanks Nirav,
I can confirm that this works when I do the compile with llc, but then when
linking to an executable with clang (patched with
http://reviews.llvm.org/D20352 and compiler-rt patched with
http://reviews.llvm.org/D21612) on Linux, I'm getting something different.
Here's a sample of the transcript, and what I'm seeing:
--->8 clang invocation 8<---
[16-06-23 3:33:42]
2016 Apr 29
2
RFC: XRay -- A Function Call Tracing System
TL;DR: At Google we use a call tracing system called XRay which inserts
patchable instrumentation points into function entries and exits. If the
community is interested, we'd like to contribute this system to the LLVM
project. Many more details are contained in the whitepaper at:
https://storage.googleapis.com/xray-downloads/whitepaper/XRayAFunctionCallTracingSystem.pdf
Who's
2018 Jun 07
2
XRay TID mismatch when forking
Hello,
There seems to be a bug with the value of the thread ID (TID) that is
generated by XRay when calling fork(). The value of the TID of the child
has the same TID as its parent (this is seen in the “thread: “ field of the
YAML output produced by the llvm-xray tool). This is a problem as the trace
generated contains the same TID for the parent and children processes,
making it difficult to
2018 Jun 08
2
XRay FDR mode doesn’t log main thread calls
Hello,
I am initializing FDR mode and finalizing/flushing the buffers manually.
XRay does not log calls from the main thread unless there is a function
call after __xray_log_finalize(). This behavior is abnormal since one would
expect the trace file to contain all function calls made up to the point
when __xray_log_finalize() is called. To demonstrate this behavior, I have
taken the test case
2016 Jun 17
2
RFC: Comprehensive Static Instrumentation
On Fri, Jun 17, 2016 at 5:42 AM Matthias Braun via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Some of this overlaps with the features in XRay (
> http://lists.llvm.org/pipermail/llvm-dev/2016-April/098901.html).
>
>
Matthias beat me to it!
>From reading the RFC, it seems that some of what XRay is doing on the
instrumentation side is very similar to what CSI enables. The
2016 Aug 26
2
[XRay][RFC] Tooling for XRay Trace Analysis
> On 26 Aug 2016, at 03:26, Chris Bieneman <cbieneman at apple.com> wrote:
>
> I totally did not mean to make the response off list.
>
Thanks Chris, I'm adding the list to this response. Those interested should see the short discussion quoted below.
Adding Chandler explicitly for points raised by Chris below. Thoughts?
Cheers
-- Dean
>
>> On Aug 24, 2016, at
2016 Aug 23
2
[XRay][RFC] Tooling for XRay Trace Analysis
Hi llvm-dev,
I've been implementing a tool for analysing XRay traces. A recap of XRay's original RFC [0] mentions a tool that does function call accounting as a starting point. This is implemented currently in D21987 [1], and is being reviewed by David Blaikie.
One key issue in that review is the dependency between the log format determined by the XRay runtime implementation in
2016 Sep 09
2
[XRay][RFC] Tooling for XRay Trace Analysis
> On 7 Sep 2016, at 01:21, David Blaikie <dblaikie at gmail.com> wrote:
>
> (sorry for the delay)
>
All good, thanks Dave!
> On Tue, Aug 23, 2016 at 1:05 AM Dean Michael Berris <dean.berris at gmail.com <mailto:dean.berris at gmail.com>> wrote:
> Hi llvm-dev,
>
> I've been implementing a tool for analysing XRay traces. A recap of XRay's
2016 Sep 09
2
[XRay][RFC] Tooling for XRay Trace Analysis
On Thu, Sep 8, 2016 at 11:34 PM Dean Michael Berris <dean.berris at gmail.com>
wrote:
>
> > On 9 Sep 2016, at 12:35, Dean Michael Berris <dean.berris at gmail.com>
> wrote:
> >
> >
> >
> >> On 7 Sep 2016, at 01:21, David Blaikie <dblaikie at gmail.com> wrote:
> >>
> >> But I take it you mean (as detailed later) to have a
2017 Mar 13
5
Use of the C++ standard library in XRay compiler-rt
On Sun, Mar 12, 2017, 4:10 PM Dean Michael Berris <dean.berris at gmail.com>
wrote:
>
> > On 9 Mar 2017, at 09:32, David Blaikie via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
> >
> > I agree that we should clean up the standard library usage even just for
> consistency.
> >
>
> +1 -- now that I think about it, it should be fairly doable
2016 Jun 22
0
x86: How to Force 2-byte `jmp` instruction in lowering
Hmm. Odd. I just rebuilt from scratch and it seems to work with
the test/CodeGen/X86/xray-attribute-instrumentation.ll test case outputing
straight to obj:
llc -filetype=obj -o ~/a.o -mtriple=x86_64-apple-macosx <
test/CodeGen/X86/xray-attribute-instrumentation.ll
What test case are you using?
In any case, the issue appears to be that llvm doesn't realize that the
target address is
2019 Jan 07
2
[Xray] Help with Xray
On Mon, Jan 7, 2019 at 3:21 PM Dean Michael Berris <dean.berris at gmail.com>
wrote:
> On Mon, Jan 7, 2019 at 8:43 PM Dangeti Tharun kumar
> <cs15mtech11002 at iith.ac.in> wrote:
> >
> > Hi Dean,
> >
> > I have tried with -instr-map-1 and -instr-map-2, it didn't work.
> >
>
> Yeah, I'm looking through the code and it looks like