Re: gdb and dlopen

Daniel Jacobowitz
2001-10-17T11:15:00Z

On Wed, Oct 17, 2001 at 11:42:07AM -0400, Andrew Cagney wrote:
> >thread_db is, plain and simply, horribly slow. We could speed it up
> >tremendously if we cached memory reads from the child across periods
> >where we knew it was safe to do so; I'll have to think about how to do
> >this. Meanwhile, the real speed penalty seems to be:
>
> Look at dcache.[hc].

Well, if I use dcache by creating an appropriate memory region, I go
from 7.17 seconds execution time to 5.46 seconds. We still do a load
of unnecessary memory traffic, but at least it isn't quite so heinous.

Is there any reason not to define a Unix inferior process's memory
space as cached by default? I suppose that for mmap'd regions and for
SYSV style shared memory we might lose, but I consider still consider
this a reasonable behavior, worth documenting but not worth accepting a
performance penalty for.

--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer