record-btrace: add bts buffer size configuration option

record-btrace: add bts buffer size configuration option

Allow the size of the branch trace ring buffer to be defined by the
user.  The specified buffer size will be used when BTS tracing is
enabled for new threads.

The obtained buffer size may differ from the requested size.  The
actual buffer size for the current thread is shown in the "info record"
command.

Bigger buffers mean longer traces, but also longer processing time.

2015-02-09  Markus Metzger  <markus.t.metzger@intel.com>

	* btrace.c (parse_xml_btrace_conf_bts): Add size.
	(btrace_conf_bts_attributes): New.
	(btrace_conf_children): Add attributes.
	* common/btrace-common.h (btrace_config_bts): New.
	(btrace_config)<bts>: New.
	(btrace_config): Update comment.
	* nat/linux-btrace.c (linux_enable_btrace, linux_enable_bts):
	Use config.
	* features/btrace-conf.dtd: Increment version.  Add size
	attribute to bts element.
	* record-btrace.c (set_record_btrace_bts_cmdlist,
	show_record_btrace_bts_cmdlist): New.
	(record_btrace_adjust_size, record_btrace_print_bts_conf,
	record_btrace_print_conf, cmd_set_record_btrace_bts,
	cmd_show_record_btrace_bts): New.
	(record_btrace_info): Call record_btrace_print_conf.
	(_initialize_record_btrace): Add commands.
	* remote.c: Add PACKET_Qbtrace_conf_bts_size enum.
	(remote_protocol_features): Add Qbtrace-conf:bts:size packet.
	(btrace_sync_conf): Synchronize bts size.
	(_initialize_remote): Add Qbtrace-conf:bts:size packet.
	* NEWS: Announce new commands and new packets.

doc/
	* gdb.texinfo (Branch Trace Configuration Format): Add size.
	(Process Record and Replay): Describe new set|show commands.
	(General Query Packets): Describe Qbtrace-conf:bts:size packet.

testsuite/
	* gdb.btrace/buffer-size: New.

gdbserver/
	* linux-low.c (linux_low_btrace_conf): Print size.
	* server.c (handle_btrace_conf_general_set): New.
	(hanle_general_set): Call handle_btrace_conf_general_set.
	(handle_query): Report Qbtrace-conf:bts:size as supported.