Re: [PATCH v2 36/40] tracing: Remove lookups from tracing_map hitcount
From: Tom Zanussi
Date: Tue Sep 12 2017 - 10:16:26 EST
Hi Masami,
On Tue, 2017-09-12 at 11:16 +0900, Masami Hiramatsu wrote:
> Hi Tom,
>
> On Tue, 5 Sep 2017 16:57:48 -0500
> Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx> wrote:
>
> > Lookups inflate the hitcount, making it essentially useless. Only
> > inserts and updates should really affect the hitcount anyway, so
> > explicitly filter lookups out.
> >
> > Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
> > ---
> > kernel/trace/tracing_map.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
> > index a4e5a56..f8e2338 100644
> > --- a/kernel/trace/tracing_map.c
> > +++ b/kernel/trace/tracing_map.c
> > @@ -538,7 +538,8 @@ static inline bool keys_match(void *key, void *test_key, unsigned key_size)
> > if (test_key && test_key == key_hash) {
> > if (entry->val &&
> > keys_match(key, entry->val->key, map->key_size)) {
> > - atomic64_inc(&map->hits);
> > + if (!lookup_only)
> > + atomic64_inc(&map->hits);
>
> Is this a kind of bugfix for current code?
> If so, such patch can be posted in separate series.
>
Yeah, that sounds like a good idea - will separate this out along with
another one or two in the same boat..
Thanks,
Tom