Messages in this thread | | | Date | Wed, 11 Jun 2014 10:05:24 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 2/2] tracing: Do not copy hash if O_TRUNC is set |
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On Wed, 11 Jun 2014 17:06:54 +0900 Namhyung Kim <namhyung@kernel.org> wrote:
> When a filter file is open for writing and O_TRUNC is set, there's no > need to copy and free the filter entries. >
Nice cleanup. I'll add it for 3.17.
Thanks,
-- Steve
> 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; >
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