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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham 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 E311FC10F03 for ; Thu, 25 Apr 2019 08:43:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB293217D7 for ; Thu, 25 Apr 2019 08:43:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556181786; bh=xqWwpBW/0A7P0WH34h69zVG4+D1R5HG9KGDtDoOwYeI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=nxuCBCfNPKmBbzgB0JQe1XuxiuC7+ZdfpKrha21npKEurqn5sS0l9cnDPeg8hJccs w/5mcsmSPz2xlkGSxJ6MiGyuwUg2fTM0DDtsq4URtm7j3IjqmDOwT6d3M1pXe86HvN FL0SBGHww6flHdgljr89j6pwd9WCYUZjH7CnKc8o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726764AbfDYInF (ORCPT ); Thu, 25 Apr 2019 04:43:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:48796 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725965AbfDYInE (ORCPT ); Thu, 25 Apr 2019 04:43:04 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id A9156AD18; Thu, 25 Apr 2019 08:43:03 +0000 (UTC) Date: Thu, 25 Apr 2019 10:43:02 +0200 From: Michal Hocko To: "Du, Fan" Cc: "akpm@linux-foundation.org" , "Wu, Fengguang" , "Williams, Dan J" , "Hansen, Dave" , "xishi.qiuxishi@alibaba-inc.com" , "Huang, Ying" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH 5/5] mm, page_alloc: Introduce ZONELIST_FALLBACK_SAME_TYPE fallback list Message-ID: <20190425084302.GQ12751@dhcp22.suse.cz> References: <1556155295-77723-1-git-send-email-fan.du@intel.com> <1556155295-77723-6-git-send-email-fan.du@intel.com> <20190425063807.GK12751@dhcp22.suse.cz> <5A90DA2E42F8AE43BC4A093BF067884825785F04@SHSMSX104.ccr.corp.intel.com> <20190425074841.GN12751@dhcp22.suse.cz> <5A90DA2E42F8AE43BC4A093BF067884825785F50@SHSMSX104.ccr.corp.intel.com> <20190425080936.GP12751@dhcp22.suse.cz> <5A90DA2E42F8AE43BC4A093BF067884825785FA5@SHSMSX104.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5A90DA2E42F8AE43BC4A093BF067884825785FA5@SHSMSX104.ccr.corp.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 25-04-19 08:20:28, Du, Fan wrote: > > > >-----Original Message----- > >From: owner-linux-mm@kvack.org [mailto:owner-linux-mm@kvack.org] On > >Behalf Of Michal Hocko > >Sent: Thursday, April 25, 2019 4:10 PM > >To: Du, Fan > >Cc: akpm@linux-foundation.org; Wu, Fengguang ; > >Williams, Dan J ; Hansen, Dave > >; xishi.qiuxishi@alibaba-inc.com; Huang, Ying > >; linux-mm@kvack.org; linux-kernel@vger.kernel.org > >Subject: Re: [RFC PATCH 5/5] mm, page_alloc: Introduce > >ZONELIST_FALLBACK_SAME_TYPE fallback list > > > >On Thu 25-04-19 07:55:58, Du, Fan wrote: > >> >> PMEM is good for frequently read accessed page, e.g. page cache(implicit > >> >> page > >> >> request), or user space data base (explicit page request) > >> >> For now this patch create GFP_SAME_NODE_TYPE for such cases, > >additional > >> >> Implementation will be followed up. > >> > > >> >Then simply configure that NUMA node as movable and you get these > >> >allocations for any movable allocation. I am not really convinced a new > >> >gfp flag is really justified. > >> > >> Case 1: frequently write and/or read accessed page deserved to DRAM > > > >NUMA balancing > > Sorry, I mean page cache case here. > Numa balancing works for pages mapped in pagetable style. I would still expect that a remote PMEM node access latency is smaller/comparable to the real storage so a promoting part is not that important for the unmapped pagecache. Maybe I am wrong here but that really begs for some experiments before we start adding special casing. -- Michal Hocko SUSE Labs