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Re: [RFC] problem fetching inferior memory due to breakpoint
- From: Daniel Jacobowitz <drow at false dot org>
- To: Joel Brobecker <brobecker at adacore dot com>
- Cc: gdb-patches at sources dot redhat dot com
- Date: Wed, 26 Apr 2006 15:19:46 -0400
- Subject: Re: [RFC] problem fetching inferior memory due to breakpoint
- References: <20060426190517.GA930@adacore.com>
On Wed, Apr 26, 2006 at 12:05:17PM -0700, Joel Brobecker wrote:
> We actually scan the function prologue during the step operation as
> opposed to during the "bt", because we need to determine where we are,
> and that causes us to create the frame ID for frame 0, which means
> scanning the function prologue (not actually verified, all from memory,
> may be incorrect - but the fact is correct: we compute the frame ID
> during the step).
Which seriously blows for performance.
> I'm not exactly sure yet as to why we don't see this problem on x86-linux.
> But all works fine there as far as I can tell.
Try removing .debug_frame, to trigger the prologue analyzer?
> I looked at the gdb-patches archives, and Andrew said at the time
> that we should use get_frame_memory. The problem is that I don't see
> how get_frame_memory() will help, since all it does is calling
> read_memory(), which brings us back to our initial problem.
Try safe_frame_unwind_memory, the other caller of
deprecated_read_memory_nobpt. Many other prologue analyzers already
seem to use that.
--
Daniel Jacobowitz
CodeSourcery