Add fast tracepoints.

	* arch-utils.h (default_fast_tracepoint_valid_at): Declare.
	* arch-utils.c (default_fast_tracepoint_valid_at): New function.
	* breakpoint.h (enum bptype): Add bp_fast_tracepoint.
	* breakpoint.c (tracepoint_type): New function.
	(ALL_TRACEPOINTS): Use it.
	(should_be_inserted): Ditto.
	(bpstat_check_location): Ditto.
	(print_one_breakpoint_location): Ditto.
	(user_settable_breakpoint): Ditto.
	(set_breakpoint_location_function): Ditto.
	(disable_breakpoints_in_shlibs): Ditto.
	(delete_trace_command): Ditto.
	(print_it_typical): Add bp_fast_tracepoint case.
	(bpstat_what): Ditto.
	(print_one_breakpoint_location): Ditto.
	(allocate_bp_location): Ditto.
	(mention): Ditto.
	(breakpoint_re_set_one): Ditto.
	(disable_command): Ditto.
	(enable_command): Ditto.
	(check_fast_tracepoint_sals): New function.
	(break_command_really): Call it.
	(ftrace_command): New function.
	(_initialize_breakpoint): Add ftrace command.
	* gdbarch.sh (fast_tracepoint_valid_at): New.
	* gdbarch.h, gdbarch.c: Regenerate.
	* i386-tdep.c (i386_fast_tracepoint_valid_at): New function.
	(i386_gdbarch_init): Use it.
	* remote.c (struct remote_state): New field fast_tracepoints.
	(PACKET_FastTracepoints): New packet config type.
	(remote_fast_tracepoint_feature): New function.
	(remote_protocol_features): Add FastTracepoints.
	(remote_supports_fast_tracepoints): New function.
	(_initialize_remote): Add FastTracepoints.
	* tracepoint.c (download_tracepoint): Add fast tracepoint option.
	* NEWS: Mention fast tracepoints.

	* gdb.texinfo (Create and Delete Tracepoints): Describe fast
	tracepoints.
	(Tracepoint Packets): Describe remote protocol for fast
	tracepoints.

	* gdb.trace/tracecmd.exp: Test ftrace.

1 files changed, 16 insertions, 1 deletions

diff --git a/gdb/NEWS b/gdb/NEWS
index 184c4e6..544a1aa 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -36,7 +36,19 @@ Renesas RX			rx
   tracepoint actions and condition expressions.  Use the "tvariable"
   command to create, and "info tvariables" to view; see "Trace State
   Variables" in the manual for more detail.
-  
+
+* Fast tracepoints
+
+  GDB now includes an option for defining fast tracepoints, which
+  targets may implement more efficiently, such as by installing a jump
+  into the target agent rather than a trap instruction.  The resulting
+  speedup can be by two orders of magnitude or more, although the
+  tradeoff is that some program locations on some target architectures
+  might not allow fast tracepoint installation, for instance if the
+  instruction to be replaced is shorter than the jump.  To request a
+  fast tracepoint, use the "ftrace" command, with syntax identical to
+  the regular trace command.
+
 * Changed commands
 
 disassemble
@@ -101,6 +113,9 @@ teval EXPR, ...
   Evaluate the given expressions without collecting anything into the
   trace buffer. (Valid in tracepoint actions only.)
 
+ftrace FN / FILE:LINE / *ADDR
+  Define a fast tracepoint at the given function, line, or address.
+
 * New options
 
 set follow-exec-mode new|same