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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B82BBC433E0 for ; Wed, 23 Dec 2020 02:07:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E159225AB for ; Wed, 23 Dec 2020 02:07:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726960AbgLWCHN (ORCPT ); Tue, 22 Dec 2020 21:07:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:25545 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726068AbgLWCHN (ORCPT ); Tue, 22 Dec 2020 21:07:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608689146; 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=BTDw6F8i8Hd7yrviwj2j64uCpdlUqMClrvxGh+hRTGs=; b=hUetfDk26nwGBQzZ3P5PlVox7tNF43yFoztSytMs4FHuuYWOfkFb+rwHPx8etVXzGWdAq6 9aErymm3Vya18OFva9u7TbIgGQXUome3A+EFlDBMSv9OmIGzPXm0sjLux9Gv5rPWe4sRKY pTDpdPDhuwbXnPyK2+JuQWB2kG15NCc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-461-aWAP2yPzOnStP2DTRd0SBw-1; Tue, 22 Dec 2020 21:05:42 -0500 X-MC-Unique: aWAP2yPzOnStP2DTRd0SBw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 337AE107ACF6; Wed, 23 Dec 2020 02:05:41 +0000 (UTC) Received: from localhost (ovpn-13-111.pek2.redhat.com [10.72.13.111]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3BFA06F988; Wed, 23 Dec 2020 02:05:36 +0000 (UTC) Date: Wed, 23 Dec 2020 10:05:34 +0800 From: Baoquan He To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, gopakumarr@vmware.com, rppt@kernel.org, david@redhat.com Subject: Re: [PATCH v2 0/5] Fix the incorrect memmep defer init handling and do some cleanup Message-ID: <20201223020534.GA2205@MiWiFi-R3L-srv> References: <20201220082754.6900-1-bhe@redhat.com> <20201222174658.a2d08ca723a20587467792d9@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201222174658.a2d08ca723a20587467792d9@linux-foundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/22/20 at 05:46pm, Andrew Morton wrote: > On Sun, 20 Dec 2020 16:27:49 +0800 Baoquan He wrote: > > > VMware reported the performance regression during memmap_init() invocation. > > And they bisected to commit 73a6e474cb376 ("mm: memmap_init: iterate over > > memblock regions rather that check each PFN") causing it. > > > > https://lore.kernel.org/linux-mm/DM6PR05MB52921FF90FA01CC337DD23A1A4080@DM6PR05MB5292.namprd05.prod.outlook.com/ > > > > After investigation, it's caused by incorrect memmap init defer handling > > in memmap_init_zone() after commit 73a6e474cb376. The current > > memmap_init_zone() only handle one memory region of one zone, while > > memmap_init() iterates over all its memory regions and pass them one by > > one into memmap_init_zone() to handle. > > > > So in this patchset, patch 1/5 fixes the bug observed by VMware. Patch > > 2~5/5 clean up codes. > > accordingly. > > This series doesn't apply well to current mainline (plus, perhaps, > material which I sent to Linus today). > > So please check all that against mainline in a day or so, refresh, > retest and resend. > > Please separate the fix for the performance regression (1/5) into a > single standalone patch, ready for -stable backporting. And then a > separate 4-patch series with the cleanups for a 5.11 merge. Sure, doing now. By the way, when sending patches to linux-mm ML, which branch should I rebase them on? I usually take your akpm/master as base, thought this will make your patch picking easier. Seems my understanding is not true, akpm/master is changed very soon, we should always base patch on linus's master branch, whether patch is sending to linux-mm or not, right? Thanks Baoquan