From: Steven Rostedt Date: Wed, 3 Dec 2008 04:50:02 +0000 (-0500) Subject: ftrace: add ftrace_graph_stop() X-Git-Tag: v2.6.29-rc1~586^2~34^2~8 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=14a866c567e040ccf6240d68b083dd1dbbde63e6;p=pandora-kernel.git ftrace: add ftrace_graph_stop() Impact: new ftrace_graph_stop function While developing more features of function graph, I hit a bug that caused the WARN_ON to trigger in the prepare_ftrace_return function. Well, it was hard for me to find out that was happening because the bug would not print, it would just cause a hard lockup or reboot. The reason is that it is not safe to call printk from this function. Looking further, I also found that it calls unregister_ftrace_graph, which grabs a mutex and calls kstop machine. This would definitely lock the box up if it were to trigger. This patch adds a fast and safe ftrace_graph_stop() which will stop the function tracer. Then it is safe to call the WARN ON. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed