From: AKASHI Takahiro Date: Wed, 30 Apr 2014 09:54:33 +0000 (+0900) Subject: arm64: Add ftrace support X-Git-Tag: omap-for-v3.16/fixes-against-rc1~91^2~10^2~4 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=819e50e25d0ce8a75f5cba815416a6a8573655c4;p=pandora-kernel.git arm64: Add ftrace support This patch implements arm64 specific part to support function tracers, such as function (CONFIG_FUNCTION_TRACER), function_graph (CONFIG_FUNCTION_GRAPH_TRACER) and function profiler (CONFIG_FUNCTION_PROFILER). With 'function' tracer, all the functions in the kernel are traced with timestamps in ${sysfs}/tracing/trace. If function_graph tracer is specified, call graph is generated. The kernel must be compiled with -pg option so that _mcount() is inserted at the beginning of functions. This function is called on every function's entry as long as tracing is enabled. In addition, function_graph tracer also needs to be able to probe function's exit. ftrace_graph_caller() & return_to_handler do this by faking link register's value to intercept function's return path. More details on architecture specific requirements are described in Documentation/trace/ftrace-design.txt. Reviewed-by: Ganapatrao Kulkarni Acked-by: Will Deacon Signed-off-by: AKASHI Takahiro Signed-off-by: Will Deacon --- Reading git-diff-tree failed