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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 54BD6C433E2 for ; Fri, 26 Jun 2020 11:15:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F27720E65 for ; Fri, 26 Jun 2020 11:15:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TMYZ5TM8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728377AbgFZLPO (ORCPT ); Fri, 26 Jun 2020 07:15:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728263AbgFZLPM (ORCPT ); Fri, 26 Jun 2020 07:15:12 -0400 Received: from casper.infradead.org (unknown [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67792C08C5C1; Fri, 26 Jun 2020 04:15:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=OPLtbx4nSF+ZifTe6YUf/6ZKs4PvGHfV1P1Ne1BmY9I=; b=TMYZ5TM8uqJMUmW9EMBU5X0XlE sUmdCj+Le5O1RirUulvCJzrbBODVkrm5WB3Fi6gddS74hf5+7pDgxsKNeXGmDGnEu8Uf8Ot6TLeci akXaxHdpV7kgkX9h7CtRRKqp/P5O0h52RTuZxSwPT7v3EGZwKop0NY5fv7tde7yLI/49+/1euM6v7 5NpixGyi9vvjrq07AnGsrKu8CUaX++A4o/8WlEbsQtr7TrhMyjyfGDFoMPm8cOFokts0iU9Poaauk txHL3rMCuuB1pfOKI5qzsaxY2UJUFHZ+Ia0iCTOuH/wv4YseBtGfGa4Vhi6we2tYnvd4fAASDKWKI 8x7yR3mA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jomJ1-0006Uh-4s; Fri, 26 Jun 2020 11:14:03 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 07704301DFC; Fri, 26 Jun 2020 13:14:01 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7F78329C9595E; Fri, 26 Jun 2020 13:14:01 +0200 (CEST) Date: Fri, 26 Jun 2020 13:14:01 +0200 From: Peter Zijlstra To: Nitesh Narayan Lal Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, frederic@kernel.org, mtosatti@redhat.com, juri.lelli@redhat.com, abelits@marvell.com, bhelgaas@google.com, linux-pci@vger.kernel.org, rostedt@goodmis.org, mingo@kernel.org, tglx@linutronix.de, davem@davemloft.net, akpm@linux-foundation.org, sfr@canb.auug.org.au, stephen@networkplumber.org, rppt@linux.vnet.ibm.com, jinyuqi@huawei.com, zhangshaokun@hisilicon.com Subject: Re: [Patch v4 3/3] net: Restrict receive packets queuing to housekeeping CPUs Message-ID: <20200626111401.GE4817@hirez.programming.kicks-ass.net> References: <20200625223443.2684-1-nitesh@redhat.com> <20200625223443.2684-4-nitesh@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200625223443.2684-4-nitesh@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 25, 2020 at 06:34:43PM -0400, Nitesh Narayan Lal wrote: > From: Alex Belits > > With the existing implementation of store_rps_map(), packets are queued > in the receive path on the backlog queues of other CPUs irrespective of > whether they are isolated or not. This could add a latency overhead to > any RT workload that is running on the same CPU. > > Ensure that store_rps_map() only uses available housekeeping CPUs for > storing the rps_map. > > Signed-off-by: Alex Belits > Signed-off-by: Nitesh Narayan Lal Dave, ACK if I route this?