OProfile support is disabled

[Ryo Onodera]

OProfile suppot for LLVM is disabled. It is used for profiling JIT-ed code by LLVM.

Please enable OProfile. I created a rough patch for it. Please review.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "llvm-oprofile.patch" of this bug report has been identified as being a patch. The ubuntu-reviewers team has been subscribed to the bug report so that they can review the patch. In the event that this is in fact not a patch you can resolve this situation by removing the tag 'patch' from the bug report and editing the attachment so that it is not flagged as a patch. Additionally, if you are member of the ubuntu-reviewers team please also unsubscribe the team from this bug report.

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[Sylvestre Ledru (sylvestre)]

Next time, please report that into the debian bug tracker.

Any side effects or performance issues we should expect from it ?

[Ryo Onodera (ryoqun)]

Thanks for replying!

First of all, Ubuntu started to provide the latest OProfile (0.9.8) again after some inactivity of packaging. I'm really happy about that. Thank you very mcuh!!

Because now LLVM depends on libopagent, this bug is blocked by these following libopagent-related bugs:

Bug 1154025 Install PIC version of libbfd.a
Bug 1148682 symbol lookup error: /usr/lib/libopagent.so: undefined symbol: bfd_init

Could you also take a look at these? By resolving them, we can avoid to add the linking option "-lbfd" to configure.

Turning back to this bug, the side effects or permance issues should be minimal.

When LLVM's users aren't using OProfile related C++ LLVM classes explitly, nothing happens at runtime. Thus, thre is no performance degragation at all. Starting from LLVM 3.1, linking to libopagent is delayed by using dlopen as much as possible until when we absoluteby have to do it.

In a sense, as a side effect, we have new dependancy. Also, the binary size will be bigger a bit.

Note that I didn't but we should make libllvm3.1 and llvm-3.1-dev depend on libopagent1.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.