Re: need to focus on java performance?

[Andrew Haley <aph at redhat dot com>]

David Daney writes:
 > Andrew Haley wrote:
 > > I discovered something very interesting yesterday: Valgrind translates
 > > the DWARF info into a much faster form at load time.  This doesn't
 > > make much sense for C++, but it makes a lot of sense for java.  We
 > > could lift that code, or the idea, and put it into gcc's unwinder.
 > > 
 > 
 > I imagine that most of the stack traces are needed for security checks, 
 > and not exceptions.

It's about 50:50.

 > If stack traces are really done so much, would it make any sense to
 > compile all code with a frame pointer, and walking those instead of
 > using the DWARF unwinder?  In the recent past that was done on many
 > archetectures.  Perhaps changing it was a mistake.

Sure, but not all the code is Java code.  Sometimes we have to unwind
through code we didn't compile as part of libgcj; parts of libgcc, for
example.

Andrew.