On Fri, 13 Jan 2017 13:22:43 +0900
Namhyung Kim <namhy...@kernel.org> wrote:
> It's currently fixed to 32 and it ignores when user gives a pattern
> which match to functions more than the size. So filtering like all
> system calls or many functions with common prefix cannot be set all.
> Not sure this is right though.
Yes it's small, and there's a reason for it. So I'm giving a
conditional nack to the patch.
>
> This patch adds 'graph_filter_size' file in the tracefs to adjust the
> size. It can be changed only if the current tracer is not set.
>
> Signed-off-by: Namhyung Kim <namhy...@kernel.org>
The condition is, we need to fix ftrace_graph_addr() first.
for (i = 0; i < ftrace_graph_count; i++) {
That gets called at every function being traced. See where I'm heading
with that? ;-)
We need to create a hash table or binary search first and make that
function handle a large ftrace_graph_count before implementing your
patch. Remove the linear search, replace it with either a binary search
or a hash. But an O(n) algorithm at every function call is out of the
question.
Thanks!
-- Steve
