Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH 2/2] tracing: Do not copy hash if O_TRUNC is set | Date | Wed, 11 Jun 2014 17:06:54 +0900 |
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When a filter file is open for writing and O_TRUNC is set, there's no need to copy and free the filter entries.
Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- 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 ddfda763ded7..13885590a184 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2759,7 +2759,13 @@ 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); @@ -2768,10 +2774,6 @@ 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; -- 2.0.0
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