Re: [RFA 0/7] Improved linker-debugger interface

[Gary Benson <gbenson at redhat dot com>]

Tom Tromey wrote:
> >>>>> "Gary" == Gary Benson <gbenson@redhat.com> writes:
> Gary> A quick and dirty speed comparison yielded the following results:
> 
> Gary>   no of solibs      128     256     512     1024    2048    4096
> Gary>   --------------------------------------------------------------
> Gary>   old interface       0       1       4       12      47     185
> Gary>   new interface       0       0       2        4      10      36
> Gary>   (time in seconds)
> 
> I know we discussed this before, but I don't recall the outcome.
>
> It still looks like there is a non-linearity in there.  Do you know
> why?

Some of it is certainly because GDB stores solibs in linked lists.
There is a little bit of introduced quadratic behaviour in this patch
because target_so_ops->current_sos() is expected to return a freshly
allocated list of libraries to update_solib_list(), which either adds
them to its own list or frees them if it already has them.  This makes
sense for the standard interface, which reads everything from the
inferior into a list and returns it.  The probes interface already has
a list built by the time target_so_ops->current_sos() is called, but
it has to create a copy to return.  I spent some time trying to get
around this in July or August last year but I hit a wall.  I may have
another look at this tomorrow, as this latest patch is very different
in that area from what I was working with back then.

> It would be good to have a bug for this.

I will file one (tomorrow!)

Thanks,
Gary

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