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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B3E8C77B7C for ; Fri, 18 Aug 2023 16:01:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378379AbjHRQAt (ORCPT ); Fri, 18 Aug 2023 12:00:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355209AbjHRQA0 (ORCPT ); Fri, 18 Aug 2023 12:00:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F14E13AB9 for ; Fri, 18 Aug 2023 09:00:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 76FC1635AC for ; Fri, 18 Aug 2023 16:00:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68301C433C7; Fri, 18 Aug 2023 16:00:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692374423; bh=iP/51u+uQFWCLdwtYcMg4R1ihG1dtKyEgVl061uxXSQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mJBtD6CKFoX0BrH8Ad3opJi+b9L2DlGvibsEXsIdJTZzrk389LSv6twt1jofziuNN DfdWCMQMUucaG4I4phvDTtRCAH2doFcPDLPJTq9BRGoVv0E8GUVCJBJnw8nY5bW25p U/RQQz+W8zP4oimcao2JY5Aj10qeRRYQZDNvcO6M8hN26Zj/pb/zcmjyhLDYxOSVPa 2x2ror6HBAGtee5T8184hXFP6rK906QzYUsxANZfMS65aznToJ/DuCmUcXdylCJg6C G1yA89sAAB6YYhHOuSVD5ZWB4jcGtfcQBQN6G7moieEoDgpU12H78grZg8nmRqiMg+ /kCwdyCHVHUQw== Date: Fri, 18 Aug 2023 09:00:22 -0700 From: Jakub Kicinski To: Suman Ghosh Cc: Sunil Kovvuri Goutham , Geethasowjanya Akula , Subbaraya Sundeep Bhatta , Hariprasad Kelam , "davem@davemloft.net" , "edumazet@google.com" , "pabeni@redhat.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Linu Cherian , Jerin Jacob Kollanukkaran Subject: Re: [EXT] Re: [net PATCH V2 1/4] octeontx2-pf: Update PFC configuration Message-ID: <20230818090022.50e1c46a@kernel.org> In-Reply-To: References: <20230809070532.3252464-1-sumang@marvell.com> <20230809070532.3252464-2-sumang@marvell.com> <20230809160517.7ff84c3b@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for replying a week late, always a good use of maintainers time to swap back all the context from random conversations! On Fri, 18 Aug 2023 06:54:52 +0000 Suman Ghosh wrote: > >If there is any error in open() this will silently take the interface > >down. Can't you force a NAPI poll or some such, if the concern is a > >missed IRQ? > [Suman] I can check the return type of open() and report in case of > error. But even if we force NAPI poll we might not be able to control > the watchdog reset. If we have a running traffic and interface is up, > when we force NAPI poll, then the new packets will have updated > scheduler queue and we will still loose the completion interrupts of > the previous packets. Why does it matter that you lost an interrupt if the poll has happened. Can you describe the problem in more detail? > Do you see any issue if I handle the error situation during open() call? No, for years we have been rejecting code which does this. If the machine is under memory pressure allocating all the buffers for rings can easily fail and make the machine drop off the network. You either have to refuse to change this setting at runtime or implement prepare/commit reconfiguration model like other modern drivers, where allocations are done before the stop().