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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 D7FC2C2BB54 for ; Wed, 8 Apr 2020 01:31:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5DF4206F7 for ; Wed, 8 Apr 2020 01:31:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726492AbgDHBbn (ORCPT ); Tue, 7 Apr 2020 21:31:43 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:44326 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726420AbgDHBbn (ORCPT ); Tue, 7 Apr 2020 21:31:43 -0400 Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id DFB651210A3E3; Tue, 7 Apr 2020 18:31:42 -0700 (PDT) Date: Tue, 07 Apr 2020 18:31:42 -0700 (PDT) Message-Id: <20200407.183142.390281754035873578.davem@davemloft.net> To: khlebnikov@yandex-team.ru Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kuba@kernel.org, zeil@yandex-team.ru, tedheadster@gmail.com Subject: Re: [PATCH] net: revert default NAPI poll timeout to 2 jiffies From: David Miller In-Reply-To: <158617317267.1170.12944758673162826206.stgit@buzz> References: <158617317267.1170.12944758673162826206.stgit@buzz> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 07 Apr 2020 18:31:43 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Konstantin Khlebnikov Date: Mon, 06 Apr 2020 14:39:32 +0300 > For HZ < 1000 timeout 2000us rounds up to 1 jiffy but expires randomly > because next timer interrupt could come shortly after starting softirq. > > For commonly used CONFIG_HZ=1000 nothing changes. > > Fixes: 7acf8a1e8a28 ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning") > Reported-by: Dmitry Yakunin > Signed-off-by: Konstantin Khlebnikov Applied, thank you.