Hi Pedro,
Thanks for the review. Here is an updated patch.

> It's always good for the submission to be explicit in these
> things, and good to consider these issues upfront.  I'm interested
> in hearing your thoughts on the subject upfront, and the plans
> you had, if any.
> 
> I gave it some thought, and looked at the code to refresh a bit,
> and I think things will still work correctly if the IPA buffer is
> either smaller or larger than gdbserver's.
> 
> Running the whole set of gdb.trace tests (--directory=gdb.trace)
> with a gdbserver and IPA hacked to default to different
> buffer sizes once would provide some assurance, though
> not that much.
I have run the test cases as you mentioned and did not see any
regression. I have a plan for a future patch to handle IPA buffer
size too.

> > I noticed that packet_ok () is used with getpkt thoughout the file.  
> So I
> > removed remote_get_noisy_reply.
> 
> OTOH, tracepoint packets call remote_get_noisy_reply, for an
> ancient reason, but nowadays to so that we assist the target
> with relocation if necessary (qRelocInsn; gdbserver uses it).
This patch uses remote_get_noisy_reply now.

> >     * remote.c (remote_set_trace_buffer_size): New function.
> >     (_initialize_remote): Use it.
> 
> Missed mentioning the new remote command.
Added.

> > +@item QTBuffer:size
> > +The remote stub supports the @samp{QTBuffer:size}  
> (@pxref{QTBuffer:size})
> > +packet that allows to change the size of trace buffer.
> > +
> 
> "of the trace buffer" I think.
Fixed.

> If this fails, then $default_size is left uninitialized,
> and then further below, we'll get tcl errors for using
> an unknown variable.  The pattern we usually follow around
> such gdb_test_multiple cases, is to preinitialize the variable:
> 
>    set default_size -1
>    gdb_test_multiple "tstatus" "tstatus check 1" {
>       -re ".*Trace buffer has ($decimal) bytes of ($decimal) bytes  
> free.*" {
>           set default_size $expect_out(2,string)
>       }
>    }
> 
> and then something like,
> 
>  if { $default_size < 0 } {
>    ...
>  }
Fixed.

> 
> > +* New remote packets
> > +
> > +QTBuffer:size
> > +   Set the size of trace buffer.
> 
> Add "The remote stub reports support for this packet
> to gdb's qSupported query."
Fixed.

Thanks,
Abid

2012-03-08  Stan Shebs  <stan@codesourcery.com>
	    Hafiz Abid Qadeer  <abidh@codesourcery.com>

	gdb/
	* NEWS: Mention set and show trace-buffer-size commands.
	Mention new packet.
	* target.h (struct target_ops): New method
	to_set_trace_buffer_size.
	(target_set_trace_buffer_size): New macro.
	* target.c (update_current_target): Set up new method.
	* tracepoint.c (trace_buffer_size): New global.
	(start_tracing): Send it to the target.
	(set_trace_buffer_size): New function.
	(_initialize_tracepoint): Add new setshow for trace-buffer-size.
	* remote.c (remote_set_trace_buffer_size): New function.
	(_initialize_remote): Use it.
	(QTBuffer:size) New remote command.
	(PACKET_QTBuffer_size): New enum.
	(remote_protocol_features): Add an entry for
	PACKET_QTBuffer_size.

	gdb/gdbserver/
	* tracepoint.c (trace_buffer_size): New global.
	(DEFAULT_TRACE_BUFFER_SIZE): New define.
	(init_trace_buffer): Change to one-argument function. Allocate
	trace buffer memory.
	(handle_tracepoint_general_set): Call cmd_bigqtbuffer_size to
	handle QTBuffer:size packet.
	(cmd_bigqtbuffer_size): New function.
	(initialize_tracepoint): Call init_trace_buffer with
	DEFAULT_TRACE_BUFFER_SIZE.
	* server.c (handle_query): Add QTBuffer:size in the
	supported packets.

	gdb/doc/
	* gdb.texinfo (Starting and Stopping Trace Experiments):  
Document
	trace-buffer-size set and show commands.
	(Tracepoint Packets): Document QTBuffer:size.
	(General Query Packets): Document QTBuffer:size.

	gdb/testsuite/
	* gdb.trace/trace-buffer-size.exp: New file.
	* gdb.trace/trace-buffer-size.c: New file.