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 B113CE95A63 for ; Sat, 7 Oct 2023 16:00:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344050AbjJGQAC (ORCPT ); Sat, 7 Oct 2023 12:00:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344023AbjJGQAB (ORCPT ); Sat, 7 Oct 2023 12:00:01 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36B51BA; Sat, 7 Oct 2023 09:00:00 -0700 (PDT) Date: Sat, 7 Oct 2023 17:59:57 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1696694398; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=35TTRveXU2Ka7eoxo3UirDZ5E25/uzkse4gLA2aaRG4=; b=SEMFqg5hGSJNguDX9id9Wo/3ADKEUNIAazqz0QWmfUT1VUAk426yEbYBuuu2Bsck34Rxvr JBi6/IuLmVvwtOb9YRX7mMc4aDb80Hju6TUdLWsdEoh6WFePS6Fqv1zMmxjXWOtOQ/yPLI ANFhdYIkd6HTERjGJhCPHkKLNAK9mrw5oy9w7VQEBOvZ7jOmJk5NVIBFoOTR8YIUKnThqq +2alK5zWoRgyvDZrV+oq3aKZKRKuPIRKUbABrm3PK1nhVfck/BGxxv0Z6eGvBH1DPOoRqD gwTCdeNtJktA0Z0MyZHITjpFnERhuXaL0xvRSOgoAhwvrHcdA33Tv2I0VOVWfw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1696694398; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=35TTRveXU2Ka7eoxo3UirDZ5E25/uzkse4gLA2aaRG4=; b=v7Sxfo5oPzPYHqoTaT2fz2jGOvxx9dP2ovpzBpe0JfddaRFWxWMUYP3UKiMF2bZldMd4FH kibF+uyqJjeMANAw== From: Sebastian Andrzej Siewior To: Jakub Kicinski Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, "David S. Miller" , Eric Dumazet , Paolo Abeni , Peter Zijlstra , Thomas Gleixner , Wander Lairson Costa Subject: Re: [PATCH net-next 0/2] net: Use SMP threads for backlog NAPI (or optional). Message-ID: <20231007155957.aPo0ImuG@linutronix.de> References: <20230929162121.1822900-1-bigeasy@linutronix.de> <20231004154609.6007f1a0@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20231004154609.6007f1a0@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023-10-04 15:46:09 [-0700], Jakub Kicinski wrote: > On Fri, 29 Sep 2023 18:20:18 +0200 Sebastian Andrzej Siewior wrote: > > - Patch #2 has been removed. Removing the warning is still an option. > > > > - There are two patches in the series: > > - Patch #1 always creates backlog threads > > - Patch #2 creates the backlog threads if requested at boot time, > > mandatory on PREEMPT_RT. > > So it is either or and I wanted to show how both look like. > > > > - The kernel test robot reported a performance regression with > > loopback (stress-ng --udp X --udp-ops Y) against the RFC version. > > The regression is now avoided by using local-NAPI if backlog > > processing is requested on the local CPU. > > Not what we asked for, and it doesn't apply. Apologies if I misunderstood. You said to make it optional which I did with the static key in the second patch of this series. The first patch is indeed not what we talked about I just to show what it would look like now that there is no "delay" for backlog-NAPI on the local CPU. If the optional part is okay then I can repost only that patch against current net-next. Sebastian