diff options
| author | Karl Beldan <karl.beldan@rivierawaves.com> | 2013-11-13 10:54:19 +0100 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2013-11-25 20:52:09 +0100 |
| commit | f7d8ad81ca8c447124821e58f876d1aff996c85f (patch) | |
| tree | 27f1f34298ad2c6143f2919e684bc0b4e44411ef | |
| parent | 7a5e3fa2c81ca2fdc514c61ad90fb4e0b632258c (diff) | |
| download | blackbird-op-linux-f7d8ad81ca8c447124821e58f876d1aff996c85f.tar.gz blackbird-op-linux-f7d8ad81ca8c447124821e58f876d1aff996c85f.zip | |
mac80211: minstrels: spare numerous useless calls to get_random_bytes
ATM, only the first array value returned by get_random_bytes is used.
This change moves the call to get_random_bytes from the nested loop it
is in to its parent.
While at it, replace get_random_bytes with prandom_bytes since PRNs are
way enough for the selection process.
After this, minstrel_ht reclaims 80 PR-bytes instead of 640 R-bytes.
minstrels use sample tables to probe different rates in a randomized
manner.
minstrel_ht inits one single sample table upon registration (during
subsys_initcalls) and minstrel uses one per STA addition in minstrel.
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
| -rw-r--r-- | net/mac80211/rc80211_minstrel.c | 3 | ||||
| -rw-r--r-- | net/mac80211/rc80211_minstrel_ht.c | 3 |
2 files changed, 2 insertions, 4 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c index 7fa1b36e6202..d2f19f7e7091 100644 --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -422,10 +422,9 @@ init_sample_table(struct minstrel_sta_info *mi) memset(mi->sample_table, 0xff, SAMPLE_COLUMNS * mi->n_rates); for (col = 0; col < SAMPLE_COLUMNS; col++) { + prandom_bytes(rnd, sizeof(rnd)); for (i = 0; i < mi->n_rates; i++) { - get_random_bytes(rnd, sizeof(rnd)); new_idx = (i + rnd[i & 7]) % mi->n_rates; - while (SAMPLE_TBL(mi, new_idx, col) != 0xff) new_idx = (new_idx + 1) % mi->n_rates; diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 0a4a7c78e814..e66e9f9fd0db 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -1051,10 +1051,9 @@ init_sample_table(void) memset(sample_table, 0xff, sizeof(sample_table)); for (col = 0; col < SAMPLE_COLUMNS; col++) { + prandom_bytes(rnd, sizeof(rnd)); for (i = 0; i < MCS_GROUP_RATES; i++) { - get_random_bytes(rnd, sizeof(rnd)); new_idx = (i + rnd[i]) % MCS_GROUP_RATES; - while (sample_table[col][new_idx] != 0xff) new_idx = (new_idx + 1) % MCS_GROUP_RATES; |
