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 28970C64ED6 for ; Mon, 27 Feb 2023 10:06:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230047AbjB0KGn (ORCPT ); Mon, 27 Feb 2023 05:06:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229885AbjB0KGl (ORCPT ); Mon, 27 Feb 2023 05:06:41 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FBE614986 for ; Mon, 27 Feb 2023 02:06:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=+t0UQb+OuF/ea7hjpluYOHI5k4fqZTVVQzf1SC2bteU=; b=PJaYD/nTBbDXwpsANs1mCl8ZxZ z1pfi0i40murZWh+B7js0o+DWmEk5Yj8bUGd5kF8KSD7aXP7h7QwlTbt2+bR+fU6/b4U1tciCZf/n q/M406RgEg6GvODxJ/DMtHjZ85IxvtbBj+tzwWuBIE3Nl1qMLcYKndvoF6Li2XNM+LTiPNKgkUPd6 NioNCKns8jTqMmWKXtJUgNM4HN0Xg1PYZ1ZTEYIN+FFi/4L7QA7xtFhlVFs1rAram6d6CP0TlOXiu oIo0Z3dPWu5FH7n3+5yI5wb1IWTlLgukKt/B4b3LxzcbpraVIRW59ApJBpOP+jfkna7XRFUHYv8XD 4fl7emOA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1pWaOg-00ECOz-2W; Mon, 27 Feb 2023 10:06:18 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id A536330030B; Mon, 27 Feb 2023 11:06:16 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 8E429209F7545; Mon, 27 Feb 2023 11:06:16 +0100 (CET) Date: Mon, 27 Feb 2023 11:06:16 +0100 From: Peter Zijlstra To: Raghavendra K T Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Ingo Molnar , Mel Gorman , Andrew Morton , David Hildenbrand , rppt@kernel.org, Bharata B Rao , Disha Talreja Subject: Re: [PATCH V2 2/3] sched/numa: Enhance vma scanning logic Message-ID: References: <5f0872657ddb164aa047a2231f8dc1086fe6adf6.1675159422.git.raghavendra.kt@amd.com> <048964e8-179f-de7b-1190-831779d9911f@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 27, 2023 at 12:10:41PM +0530, Raghavendra K T wrote: > In summary: I do see that access to VMAs from disjoint sets is not fully > fair, But on the other hand it is not very bad too. There is definitely > some scope or possibility to explore/improve fairness in this area > further. Ok, might be good to summarize some of this in a comment near here, so that readers are aware of the caveat of this code. > PS: I have also tested above applying V3 patch (which incorporates your > suggestions), have not seen much deviation in observation with patch. I'll see if I can find it in this dumpester fire I call inbox :-)