From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B94EBC43381 for ; Mon, 4 Mar 2019 08:28:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A451208E4 for ; Mon, 4 Mar 2019 08:28:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551688106; bh=9zyKAxeigHwumAxttBRM4JGuddNcttnoVF7+5CAx8Zk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=t+ARB4EACDz2uUnXCV8CPuaY5s0jsA/wX1taR/nDHXoqkDiALstCQipEUMgl32i9V YKw5i9JQudp5uiFGX5s7HWRWW4HZeRa8flAeJ0Ik6B1eYAgMADxBK93IaCDNHuifiX +lB9+auBrGDGBnz7rPGP9Z8MjS2K3SVmH/zCAS7s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727429AbfCDI2Z (ORCPT ); Mon, 4 Mar 2019 03:28:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:53446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727410AbfCDI2W (ORCPT ); Mon, 4 Mar 2019 03:28:22 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 81A4F20836; Mon, 4 Mar 2019 08:28:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551688102; bh=9zyKAxeigHwumAxttBRM4JGuddNcttnoVF7+5CAx8Zk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lt9JlDvcj13fiG5BkJK2NGYCYaBrMP/gxtY+v+Jlfo+dFXgLmu9ImOVebwYb9eeVj 9BirrBgX6lClmKhTvLhPYMsYBJmR+RhzpFOQ4DUIH8WsdFmHB03qGoyuisiLD5eQez lP2d0+9mn1iEhdYlUAQnJZj/LwRzMNGZLuHtoTCM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Johannes Berg Subject: [PATCH 4.19 04/78] mac80211: Change default tx_sk_pacing_shift to 7 Date: Mon, 4 Mar 2019 09:21:47 +0100 Message-Id: <20190304081625.700212482@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190304081625.508788074@linuxfoundation.org> References: <20190304081625.508788074@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Toke Høiland-Jørgensen commit 5c14a4d05f68415af9e41a4e667d1748d41d1baf upstream. When we did the original tests for the optimal value of sk_pacing_shift, we came up with 6 ms of buffering as the default. Sadly, 6 is not a power of two, so when picking the shift value I erred on the size of less buffering and picked 4 ms instead of 8. This was probably wrong; those 2 ms of extra buffering makes a larger difference than I thought. So, change the default pacing shift to 7, which corresponds to 8 ms of buffering. The point of diminishing returns really kicks in after 8 ms, and so having this as a default should cut down on the need for extensive per-device testing and overrides needed in the drivers. Cc: stable@vger.kernel.org Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/tx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -3614,10 +3614,10 @@ void __ieee80211_subif_start_xmit(struct /* We need a bit of data queued to build aggregates properly, so * instruct the TCP stack to allow more than a single ms of data * to be queued in the stack. The value is a bit-shift of 1 - * second, so 8 is ~4ms of queued data. Only affects local TCP + * second, so 7 is ~8ms of queued data. Only affects local TCP * sockets. */ - sk_pacing_shift_update(skb->sk, 8); + sk_pacing_shift_update(skb->sk, 7); fast_tx = rcu_dereference(sta->fast_tx);