similar to: [RFC] Order File Instrumentation

On Thu, Jan 17, 2019 at 10:53 AM Xinliang David Li <davidxl at google.com> wrote: > Hi Manman, > > Ordering profiling is certainly something very useful to have to startup > time performance. GCC has something similar. > > In terms of implementation, it is possible to simply extend the edge > profiling counters by 1 for each function, and instrument the function to >

On Thu, Jan 17, 2019 at 2:47 PM Xinliang David Li <davidxl at google.com> wrote: > > > On Thu, Jan 17, 2019 at 2:32 PM Manman Ren <manman.ren at gmail.com> wrote: > >> >> >> On Thu, Jan 17, 2019 at 10:53 AM Xinliang David Li <davidxl at google.com> >> wrote: >> >>> Hi Manman, >>> >>> Ordering profiling is

On Fri, Jan 18, 2019 at 3:56 PM Manman Ren <manman.ren at gmail.com> wrote: > Some background information first, then a quick summary of what we have > discussed so far! > > Background: Facebook app is one of the biggest iOS apps. Because of this, > we want the instrumentation to be as lightweight as possible in terms of > binary size, profile data size, and runtime

I would love to see this kind of order profiling support. Using dtrace to generate function orders is actually really problematic because dtrace made tradeoffs in implementation allowing it to ignore probe execution if the performance impact is too great on the system. This can result in dtrace being non-deterministic which is not ideal for generating optimization data. Additionally if order

On Fri, Jan 18, 2019 at 9:10 PM Manman Ren <manman.ren at gmail.com> wrote: > > > On Fri, Jan 18, 2019 at 4:11 PM Xinliang David Li <davidxl at google.com> > wrote: > >> >> >> On Fri, Jan 18, 2019 at 3:56 PM Manman Ren <manman.ren at gmail.com> wrote: >> >>> Some background information first, then a quick summary of what we have

Hi llvm-dev (cc google-xray), As a follow-up to the first XRay RFC [0] introducing the technology, I've been able to recently implement a functional prototype of the major parts of the XRay functionality [1]. This RFC is limited to exploring potential alternatives to the current LLVM-side changes, with the interest of getting clear guidance for landing the changes first in LLVM. Background /

On Mon, Jun 27, 2016 at 2:53 PM Xinliang David Li <davidxl at google.com> wrote: > There is some misunderstanding about the intention of this flag. The > purpose of the flag is not to turn on profile instrumentation (which > already has -fprofile-instr-generate or -fprofile-generate for it), but to > select which instrumentors to use for PGO (IR or FE). I prefer fewer flags

On Fri, Jun 24, 2016 at 1:44 AM Eric Christopher via llvm-dev < llvm-dev at lists.llvm.org> wrote: > > > On Thu, Jun 2, 2016, 6:41 PM Xinliang David Li via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> >> Sounds fine to me, though I am not a fan of using unstable in the option. >> I think a more meaningful way (that capture the essence of the

> On 20 Jul 2016, at 20:02, C Bergström <cbergstrom at pathscale.com> wrote: > > Some general questions about X-Ray > ------------- > Is there a plan to make a separate mailing list or project around > this? Do you have a list of planned features? Interesting question -- so far we haven't decided yet whether XRay will live as another project. I'm certainly open to

There is some misunderstanding about the intention of this flag. The purpose of the flag is not to turn on profile instrumentation (which already has -fprofile-instr-generate or -fprofile-generate for it), but to select which instrumentors to use for PGO (IR or FE). I prefer fewer flags too, but sharing flags for completely different purpose does not seem like the right thing to do. David On

On Sun, Jun 26, 2016 at 10:21 PM, Dean Michael Berris <dberris at google.com> wrote: > > > On Mon, Jun 27, 2016 at 2:53 PM Xinliang David Li <davidxl at google.com> > wrote: > >> There is some misunderstanding about the intention of this flag. The >> purpose of the flag is not to turn on profile instrumentation (which >> already has

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

> On Dec 13, 2016, at 3:46 AM, Martin J. O'Riordan via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > When either ‘-pg’ or ‘-finstrument-functions’ is used, the compiler inserts the appropriate profiling hooks. This happens prior to inlining, so the hooks remain in place. Have you tried compiling with -fprofile-generate? It enables IR-based profiling instrumentation, which

Thanks Vedant, and my apologies for the delay getting back to you - work got "busy". I wasn't aware of the '-fprofile-generate' option, so thanks for point this out. I have tried running it and I can see the instrumentation hooks that it generates - I assume that there is a library I have to implement to support this, can you let me know where the source for this library

Hi, I was going through the implementation of the fasttrap provider. I found that when displaced execution happens (ie., when the instruction traced is being executed out of the scratch space) if an asynchrnous signal comes we need to defer the delivery. Can somebody explain why this is necessary and how is it implemented? Thanks in advance Saravanan S -------------- next part -------------- An

When either '-pg' or '-finstrument-functions' is used, the compiler inserts the appropriate profiling hooks. This happens prior to inlining, so the hooks remain in place. Normally this is fine, but with C++ and the heavy use of inline functions and templates, there can be a vast number of trivial functions that are normally optimised away; but with the instrumentation hooks

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

Thanks for the hint, I didn’t know about this option. That’s a great reference! However, I am trying to be a compiler/language agnostic. Also (for whatever reasons) I need a numeric ID of a function rather then its address. So the question is still opened. May I assume that the following always holds: The first basic block in a function is an entry point and the last basic block in a function is

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

Hi everyone, I run some functions using ORC JIT, now I need to add custom instrumentation. I want to add two callbacks to each function: ‘enterFunction' at the beginning and ‘leaveFunction' at the end. Intuition says that I could ‘just' insert CallInst's to the first and the last basic blocks in the function. Am I correct? Are there any other/better way to do this? Is there