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authorNamhyung Kim <namhyung@kernel.org>2014-06-11 17:06:54 +0900
committerSteven Rostedt <rostedt@goodmis.org>2014-07-01 07:13:41 -0400
commitef2fbe16ac176c21e3b3013c169e6fdb71ec56c7 (patch)
tree8344a51e21bb16d6823a94c769290bfc6645385e /kernel
parent1f61be007e16a5d60b1cf868aa30d87f181e8e14 (diff)
downloadop-kernel-dev-ef2fbe16ac176c21e3b3013c169e6fdb71ec56c7.zip
op-kernel-dev-ef2fbe16ac176c21e3b3013c169e6fdb71ec56c7.tar.gz
ftrace: Do not copy hash if O_TRUNC is set
When a filter file is open for writing and O_TRUNC is set, there's no need to copy and free the filter entries. Link: http://lkml.kernel.org/p/1402474014-28655-2-git-send-email-namhyung@kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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 e14ff4c..232b898 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3010,7 +3010,13 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag,
hash = ops->filter_hash;
if (file->f_mode & FMODE_WRITE) {
- iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
+ const int size_bits = FTRACE_HASH_DEFAULT_BITS;
+
+ if (file->f_flags & O_TRUNC)
+ iter->hash = alloc_ftrace_hash(size_bits);
+ else
+ iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
+
if (!iter->hash) {
trace_parser_put(&iter->parser);
kfree(iter);
@@ -3019,10 +3025,6 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag,
}
}
- if ((file->f_mode & FMODE_WRITE) &&
- (file->f_flags & O_TRUNC))
- ftrace_filter_reset(iter->hash);
-
if (file->f_mode & FMODE_READ) {
iter->pg = ftrace_pages_start;
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