Code relocation is not supported *by (external) profiling tools, *because mapping a pc to a function when processing the log file is hard when that function has been moving around over time. Without profiling, Code objects are relocatable.
The CHECK right below the comment you found guarantees that it is not outdated: CHECK(from.IsBytecodeArray()); would cause a crash if the function was called with a Code object. And src/flags/flag-definitions.h is where the magic happens: DEFINE_NEG_IMPLICATION(perf_prof, compact_code_space) turns off code space compaction when profiling. On Thu, Sep 12, 2019 at 2:25 AM <[email protected]> wrote: > I just found this comment on the codebase: > > // We may receive a CodeMove event if a BytecodeArray object moves. > Otherwise > // code relocation is not supported. > > ( > https://chromium.googlesource.com/v8/v8/+/refs/heads/master/src/diagnostics/perf-jit.cc#497 > ) > > I thought (optimized) code objects were allowed relocation (enabled by > default with --compact-code-space). Is this comment outdated, or is my > understanding incorrect? > > -- > -- > v8-dev mailing list > [email protected] > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google Groups > "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/v8-dev/cb765436-928c-4f29-b334-cf60581ae89f%40googlegroups.com > <https://groups.google.com/d/msgid/v8-dev/cb765436-928c-4f29-b334-cf60581ae89f%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/v8-dev/CAKSzg3QuW2X9a53ZpgmdfhVXefM%2BNecNabdkN3ikRrzQtpWcbg%40mail.gmail.com.
