From 6912daed05e1370af5253aea6f2116805c0e57f8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Wed, 23 Oct 2019 11:59:00 +0200 Subject: mac80211: Shrink the size of ack_frame_id to make room for tx_time_est MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To implement airtime queue limiting, we need to keep a running account of the estimated airtime of all skbs queued into the device. Do to this correctly, we need to store the airtime estimate into the skb so we can decrease the outstanding balance when the skb is freed. This means that the time estimate must be stored somewhere that will survive for the lifetime of the skb. To get this, decrease the size of the ack_frame_id field to 6 bits, and lower the size of the ID space accordingly. This leaves 10 bits for use for tx_time_est, which is enough to store a maximum of 4096 us, if we shift the values so they become units of 4us. Signed-off-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/157182474063.150713.16132669599100802716.stgit@toke.dk Signed-off-by: Johannes Berg --- include/net/mac80211.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/net/mac80211.h b/include/net/mac80211.h index f5996960eace..c643a19dce96 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -967,6 +967,7 @@ ieee80211_rate_get_vht_nss(const struct ieee80211_tx_rate *rate) * @band: the band to transmit on (use for checking for races) * @hw_queue: HW queue to put the frame on, skb_get_queue_mapping() gives the AC * @ack_frame_id: internal frame ID for TX status, used internally + * @tx_time_est: TX time estimate in units of 4us, used internally * @control: union part for control data * @control.rates: TX rates array to try * @control.rts_cts_rate_idx: rate for RTS or CTS @@ -1007,7 +1008,8 @@ struct ieee80211_tx_info { u8 hw_queue; - u16 ack_frame_id; + u16 ack_frame_id:6; + u16 tx_time_est:10; union { struct { -- cgit v1.2.3