Re: increase IEEE80211_CACHE_SIZE

[Peter Hessler]

OK


On 2019 Dec 28 (Sat) at 14:27:01 +0100 (+0100), Stefan Sperling wrote:
:The number of entries in the node cache is currently capped to 100.
:
:This limit is outdated. Modern hardware like iwm(4) 8265 supports 46
:distinct channels (1-13, 36-165) each of which can host multiple APs.
:
:The limit is easily reached at 36c6 which makes use of much of the
:available spectrum and provides at least 3 SSIDs on each channel:
:
:$ ifconfig iwm0 scan | grep nwid | wc -l
:  96
:
:So we may be missing out on the best AP to use.
:
:The cache uses an RB tree so performance impact should be negligible.
:
:ok?
:
:diff 5181eb992cbbf64c135f177197957b0e0b427e21 /usr/src
:blob - 7fada592641e683415ffc42cded1c8b27bf39c5c
:file + sys/net80211/ieee80211_node.h
:--- sys/net80211/ieee80211_node.h
:+++ sys/net80211/ieee80211_node.h
:@@ -39,7 +39,7 @@
: #define   IEEE80211_TRANS_WAIT5   /* transition wait */
: #define   IEEE80211_INACT_WAIT5   /* inactivity timer 
interval */
: #define   IEEE80211_INACT_MAX (300/IEEE80211_INACT_WAIT)
:-#define   IEEE80211_CACHE_SIZE100
:+#define   IEEE80211_CACHE_SIZE512
: #define   IEEE80211_CACHE_WAIT30
: #define   IEEE80211_INACT_SCAN10  /* for station mode */
: 
:

-- 
When I was a boy I was told that anybody could become President.
Now I'm beginning to believe it.
-- Clarence Darrow

increase IEEE80211_CACHE_SIZE

[Stefan Sperling]

The number of entries in the node cache is currently capped to 100.

This limit is outdated. Modern hardware like iwm(4) 8265 supports 46
distinct channels (1-13, 36-165) each of which can host multiple APs.

The limit is easily reached at 36c6 which makes use of much of the
available spectrum and provides at least 3 SSIDs on each channel:

$ ifconfig iwm0 scan | grep nwid | wc -l
  96

So we may be missing out on the best AP to use.

The cache uses an RB tree so performance impact should be negligible.

ok?

diff 5181eb992cbbf64c135f177197957b0e0b427e21 /usr/src
blob - 7fada592641e683415ffc42cded1c8b27bf39c5c
file + sys/net80211/ieee80211_node.h
--- sys/net80211/ieee80211_node.h
+++ sys/net80211/ieee80211_node.h
@@ -39,7 +39,7 @@
 #defineIEEE80211_TRANS_WAIT5   /* transition wait */
 #defineIEEE80211_INACT_WAIT5   /* inactivity timer 
interval */
 #defineIEEE80211_INACT_MAX (300/IEEE80211_INACT_WAIT)
-#defineIEEE80211_CACHE_SIZE100
+#defineIEEE80211_CACHE_SIZE512
 #defineIEEE80211_CACHE_WAIT30
 #defineIEEE80211_INACT_SCAN10  /* for station mode */