From patchwork Fri Dec 17 11:42:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Felix Fietkau X-Patchwork-Id: 12684399 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E53CAC433F5 for ; Fri, 17 Dec 2021 11:43:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235630AbhLQLnK (ORCPT ); Fri, 17 Dec 2021 06:43:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235627AbhLQLnJ (ORCPT ); Fri, 17 Dec 2021 06:43:09 -0500 Received: from nbd.name (nbd.name [IPv6:2a01:4f8:221:3d45::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C532C061574 for ; Fri, 17 Dec 2021 03:43:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=Content-Transfer-Encoding:MIME-Version:Message-Id:Date:Subject :Cc:To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=Yt68lu28p8qhSLxKJdX2Rb74vLM2/5YjejiNJAHF6zk=; b=gOWtmWg8RC94xOwGpaIA/1lJ53 /x85Ooz17cegyO5mJzgHrGwEFGqw4yoToph9uMF9e7ETs1VIfd5HTslwxOlvKaUKmUiX42qG7mO16 0oK3zK4IsU3o13ckh565X3nVjprY1UQO0T+dOQtqQseYP0IXK5jQPnlm5q021CNyoN0o=; Received: from p54ae911a.dip0.t-ipconnect.de ([84.174.145.26] helo=localhost.localdomain) by ds12 with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1myBdj-0007rY-L2; Fri, 17 Dec 2021 12:43:07 +0100 From: Felix Fietkau To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net, toke@redhat.com Subject: [PATCH] mac80211: use coarse boottime for airtime fairness code Date: Fri, 17 Dec 2021 12:42:58 +0100 Message-Id: <20211217114258.14619-1-nbd@nbd.name> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org The time values used by the airtime fairness code only need to be accurate enough to cover station activity detection. Using ktime_get_coarse_boottime_ns instead of ktime_get_boottime_ns will drop the accuracy down to jiffies intervals, but at the same time saves a lot of CPU cycles in a hot path Signed-off-by: Felix Fietkau Acked-by: Toke Høiland-Jørgensen --- net/mac80211/tx.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 278945e3e08a..cbe7d1d00a50 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -3821,7 +3821,7 @@ struct ieee80211_txq *ieee80211_next_txq(struct ieee80211_hw *hw, u8 ac) { struct ieee80211_local *local = hw_to_local(hw); struct airtime_sched_info *air_sched; - u64 now = ktime_get_boottime_ns(); + u64 now = ktime_get_coarse_boottime_ns(); struct ieee80211_txq *ret = NULL; struct airtime_info *air_info; struct txq_info *txqi = NULL; @@ -3948,7 +3948,7 @@ void ieee80211_update_airtime_weight(struct ieee80211_local *local, u64 weight_sum = 0; if (unlikely(!now)) - now = ktime_get_boottime_ns(); + now = ktime_get_coarse_boottime_ns(); lockdep_assert_held(&air_sched->lock); @@ -3974,7 +3974,7 @@ void ieee80211_schedule_txq(struct ieee80211_hw *hw, struct ieee80211_local *local = hw_to_local(hw); struct txq_info *txqi = to_txq_info(txq); struct airtime_sched_info *air_sched; - u64 now = ktime_get_boottime_ns(); + u64 now = ktime_get_coarse_boottime_ns(); struct airtime_info *air_info; u8 ac = txq->ac; bool was_active; @@ -4032,7 +4032,7 @@ static void __ieee80211_unschedule_txq(struct ieee80211_hw *hw, if (!purge) airtime_set_active(air_sched, air_info, - ktime_get_boottime_ns()); + ktime_get_coarse_boottime_ns()); rb_erase_cached(&txqi->schedule_order, &air_sched->active_txqs); @@ -4120,7 +4120,7 @@ bool ieee80211_txq_may_transmit(struct ieee80211_hw *hw, if (RB_EMPTY_NODE(&txqi->schedule_order)) goto out; - now = ktime_get_boottime_ns(); + now = ktime_get_coarse_boottime_ns(); /* Like in ieee80211_next_txq(), make sure the first station in the * scheduling order is eligible for transmission to avoid starvation.