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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72634C433F5 for ; Tue, 29 Mar 2022 14:31:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C3D628D0002; Tue, 29 Mar 2022 10:31:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BEBF38D0001; Tue, 29 Mar 2022 10:31:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AB38E8D0002; Tue, 29 Mar 2022 10:31:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0100.hostedemail.com [216.40.44.100]) by kanga.kvack.org (Postfix) with ESMTP id 964B48D0001 for ; Tue, 29 Mar 2022 10:31:15 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 482D61828D825 for ; Tue, 29 Mar 2022 14:31:15 +0000 (UTC) X-FDA: 79297661310.22.AAF1729 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by imf19.hostedemail.com (Postfix) with ESMTP id D331E1A0013 for ; Tue, 29 Mar 2022 14:31:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648564273; x=1680100273; h=message-id:date:mime-version:to:cc:references:from: subject:in-reply-to:content-transfer-encoding; bh=MPEyK90txtRaPxxSHUlpyihpzVwxdEsPaW015RjFxuo=; b=Bcr/Qf4Q1Va/0RzCtwTGoodi9ntiEE8zEtWDsOxIJR5enMPcjfYeL/RM Xpgx8+K1c2odwzOeThkBPpuT5BzUTSeHsaR8CdA7AnYXs9sEq7WQ1uMy+ /WNI48sTPjzF1aMwYtplj2MboZu/lcuLity1ju0gShKS30GoPunB4dFsZ 8iNq+51fbXr95gBOkwBEeB+SgTLWhBeLuyQUuGP/MNqU50vWcfIa9QXI0 eK1aWXV0wNkVeeOpb9Rz35NVQryqzP3M6lN4vQi6jVtsPWBzt9i+1j0du 8XtAgBzsAqn9qkMEP+Ev+393U2K69wN5REIzkjn3SXiI8qCzLi5nbWNA2 g==; X-IronPort-AV: E=McAfee;i="6200,9189,10301"; a="246753433" X-IronPort-AV: E=Sophos;i="5.90,220,1643702400"; d="scan'208";a="246753433" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Mar 2022 07:31:11 -0700 X-IronPort-AV: E=Sophos;i="5.90,220,1643702400"; d="scan'208";a="604810742" Received: from acstuden-mobl.amr.corp.intel.com (HELO [10.209.45.17]) ([10.209.45.17]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Mar 2022 07:31:11 -0700 Message-ID: <55161160-1084-c81d-d116-00f5bcaa1268@intel.com> Date: Tue, 29 Mar 2022 07:31:12 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Content-Language: en-US To: Jagdish Gediya , linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, baolin.wang@linux.alibaba.com, dave.hansen@linux.intel.com, ying.huang@intel.com References: <20220329115222.8923-1-jvgediya@linux.ibm.com> From: Dave Hansen Subject: Re: [PATCH] mm: migrate: set demotion targets differently In-Reply-To: <20220329115222.8923-1-jvgediya@linux.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: D331E1A0013 X-Stat-Signature: 8qgku64erhydtqqxmoqijb76zdz3wqd4 Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b="Bcr/Qf4Q"; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf19.hostedemail.com: domain of dave.hansen@intel.com has no SPF policy when checking 134.134.136.20) smtp.mailfrom=dave.hansen@intel.com X-Rspam-User: X-HE-Tag: 1648564273-374671 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 3/29/22 04:52, Jagdish Gediya wrote: > The current implementation to identify the demotion > targets limits some of the opportunities to share > the demotion targets between multiple source nodes. This changelog is a bit unsatisfying. It basically says: the current code isn't working, throw some more code at the problem. I'd love to see some more information about *why* the current code doesn't work. Is it purely a bug or was it mis-designed? I actually wrote it intending for it to handle cases like you describe while not leaving lots of nodes without demotion targets.