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authorSteven Rostedt <srostedt@redhat.com>2011-04-29 22:35:33 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2011-06-03 10:33:35 +0900
commite5664c3da9affbcca581c9a9d4a7a5dae3ca8826 (patch)
tree4f5bdec4e39f80d8d4e0eb38b790169b88aaa1a2 /kernel
parentad8ba6a764a5bb3a1e6f878b489b7842081e33fc (diff)
ftrace: Only update the function code on write to filter files
commit 058e297d34a404caaa5ed277de15698d8dc43000 upstream. 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. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/ftrace.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 888b611897d3..9803b68dbc31 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2414,14 +2414,16 @@ 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;
}