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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 A7278C433E2 for ; Tue, 1 Sep 2020 00:16:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8ACE9207EA for ; Tue, 1 Sep 2020 00:16:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726074AbgIAAQP (ORCPT ); Mon, 31 Aug 2020 20:16:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725872AbgIAAQP (ORCPT ); Mon, 31 Aug 2020 20:16:15 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49B16C061573 for ; Mon, 31 Aug 2020 17:16:15 -0700 (PDT) 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 5B16512985931; Mon, 31 Aug 2020 16:59:28 -0700 (PDT) Date: Mon, 31 Aug 2020 17:16:13 -0700 (PDT) Message-Id: <20200831.171613.1392501036623240615.davem@davemloft.net> To: kuba@kernel.org Cc: snelson@pensando.io, netdev@vger.kernel.org Subject: Re: [PATCH net-next 2/5] ionic: smaller coalesce default From: David Miller In-Reply-To: <20200831165054.6d16f0dd@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> References: <20200831233558.71417-1-snelson@pensando.io> <20200831233558.71417-3-snelson@pensando.io> <20200831165054.6d16f0dd@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> X-Mailer: Mew version 6.8 on Emacs 26.3 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 [2620:137:e000::1:9]); Mon, 31 Aug 2020 16:59:28 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jakub Kicinski Date: Mon, 31 Aug 2020 16:50:54 -0700 > On Mon, 31 Aug 2020 16:35:55 -0700 Shannon Nelson wrote: >> diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h >> index 9e2ac2b8a082..2b2eb5f2a0e5 100644 >> --- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h >> +++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h >> @@ -16,7 +16,7 @@ >> #define IONIC_DEF_TXRX_DESC 4096 >> #define IONIC_LIFS_MAX 1024 >> #define IONIC_WATCHDOG_SECS 5 >> -#define IONIC_ITR_COAL_USEC_DEFAULT 64 >> +#define IONIC_ITR_COAL_USEC_DEFAULT 8 > > 8 us interrupt coalescing does not hurt general operations?! No way. > > It's your customers who'll get hurt here, so your call, but I seriously > doubt this. Unless the unit is not usec? Agreed, 8usec is really really low. You won't get much coalescing during bulk transfers with a value like that, eliminating the gain from coalescing in the first place.