From 058e297d34a404caaa5ed277de15698d8dc43000 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 29 Apr 2011 22:35:33 -0400 Subject: [PATCH] ftrace: Only update the function code on write to filter files If function tracing is enabled, a read of the filter files will cause the call to stop_machine to update the function trace sites. It should only call stop_machine on write. Cc: stable@kernel.org Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index ee24fa1935ac..666880d051ef 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2413,14 +2413,16 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable) ftrace_match_records(parser->buffer, parser->idx, enable); } - mutex_lock(&ftrace_lock); - if (ftrace_start_up && ftrace_enabled) - ftrace_run_update_code(FTRACE_ENABLE_CALLS); - mutex_unlock(&ftrace_lock); - trace_parser_put(parser); kfree(iter); + if (file->f_mode & FMODE_WRITE) { + mutex_lock(&ftrace_lock); + if (ftrace_start_up && ftrace_enabled) + ftrace_run_update_code(FTRACE_ENABLE_CALLS); + mutex_unlock(&ftrace_lock); + } + mutex_unlock(&ftrace_regex_lock); return 0; } -- 2.20.1