2016-12-14 16:30:54

by Koen Vandeputte

Subject: [PATCH] mac80211: only alloc mem if a station doesnt exist yet

This speeds up the function in case a station already exists by avoiding
calling an expensive kzalloc just to free it again after the next check.

Signed-off-by: Koen Vandeputte <[email protected]>
---
net/mac80211/sta_info.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 1711bae..0a42e6e 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -513,23 +513,23 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
{
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
- struct station_info *sinfo;
+ struct station_info *sinfo = NULL;
int err = 0;

lockdep_assert_held(&local->sta_mtx);

- sinfo = kzalloc(sizeof(struct station_info), GFP_KERNEL);
- if (!sinfo) {
- err = -ENOMEM;
- goto out_err;
- }
-
/* check if STA exists already */
if (sta_info_get_bss(sdata, sta->sta.addr)) {
err = -EEXIST;
goto out_err;
}

+ sinfo = kzalloc(sizeof(struct station_info), GFP_KERNEL);
+ if (!sinfo) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+
local->num_sta++;
local->sta_generation++;
smp_mb();
--
2.7.4

2016-12-15 09:57:44

by Johannes Berg

Subject: Re: [PATCH] mac80211: only alloc mem if a station doesnt exist yet

On Wed, 2016-12-14 at 17:28 +0100, Koen Vandeputte wrote:
> This speeds up the function in case a station already exists by
> avoiding
> calling an expensive kzalloc just to free it again after the next
> check.

It's not like this is called often, but yeah - still makes sense.

Applied.

johannes