From d1e23c9456b2881b71732594f4cdb52d78aedecb Mon Sep 17 00:00:00 2001
From: Denis Kenzior <denkenz@gmail.com>
Date: Mon, 21 May 2018 10:31:13 -0500
Subject: [PATCH] nl80211: Optimize cfg80211_bss_expire invocations
Git-commit: d1e23c9456b2881b71732594f4cdb52d78aedecb
Patch-mainline: v4.18-rc1
References: FATE#326294
Only invoke cfg80211_bss_expire on the first nl80211_dump_scan
invocation to avoid (likely) redundant processing.
Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/wireless/nl80211.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index a3dcea2fbd7a..451f12ecb894 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -8100,7 +8100,15 @@ static int nl80211_dump_scan(struct sk_buff *skb, struct netlink_callback *cb)
wdev_lock(wdev);
spin_lock_bh(&rdev->bss_lock);
- cfg80211_bss_expire(rdev);
+
+ /*
+ * dump_scan will be called multiple times to break up the scan results
+ * into multiple messages. It is unlikely that any more bss-es will be
+ * expired after the first call, so only call only call this on the
+ * first dump_scan invocation.
+ */
+ if (start == 0)
+ cfg80211_bss_expire(rdev);
cb->seq = rdev->bss_generation;
--
2.19.2