On 26.01.2018 11:23, Andres Freund wrote:
Hi,
Thanks for testing things out!
Thank you for this work.
One more question: do you have any idea how to profile JITed code?
There is no LLVMOrcRegisterPerf in LLVM 5, so jit_profiling_support
option does nothing.
And without it perf is not able to unwind stack trace for generated code.
A attached the produced profile, looks like "unknown" bar corresponds to
JIT code.
There is NoFramePointerElim option in LLVMMCJITCompilerOptions
structure, but it requires use of ExecutionEngine.
Something like this:
mod = llvm_mutable_module(context);
{
struct LLVMMCJITCompilerOptions options;
LLVMExecutionEngineRef jit;
char* error;
LLVMCreateExecutionEngineForModule(&jit, mod, &error);
LLVMInitializeMCJITCompilerOptions(&options, sizeof(options));
options.NoFramePointerElim = 1;
LLVMCreateMCJITCompilerForModule(&jit, mod, &options,
sizeof(options),
&error);
}
...
But you are compiling code using LLVMOrcAddEagerlyCompiledIR
and I find no way to pass no-omit-frame pointer option here.
--
Konstantin Knizhnik
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
