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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 09C44C54E67 for ; Thu, 28 Mar 2024 08:33:40 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=ZI+74/pc; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=ZI+74/pc; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4V4xdb4pShz3vhX for ; Thu, 28 Mar 2024 19:33:39 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=ZI+74/pc; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=ZI+74/pc; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=redhat.com (client-ip=170.10.133.124; helo=us-smtp-delivery-124.mimecast.com; envelope-from=bhe@redhat.com; receiver=lists.ozlabs.org) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4V4xck3T3Rz3vYH for ; Thu, 28 Mar 2024 19:32:53 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1711614770; 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=YU98x6HKPS4cGaJBRCphv0qa0ztW8Hkud3KMpoGM99k=; b=ZI+74/pctXFNa6WO8YAbdAb3gXtbEk87hsx9wAH0UKrqFhYKtkUnur36MOK+9RaIQSPOdA iE9EvzGyl0Ly4MK5U6f2dBh0YDJCUk0R0ITx8U5uy4JD3IuBKkRsHF8GB0Z22W4/phVeSk Cp7dK7KVTXJ7lGz0DGkh09NuAVLe5Xs= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1711614770; 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=YU98x6HKPS4cGaJBRCphv0qa0ztW8Hkud3KMpoGM99k=; b=ZI+74/pctXFNa6WO8YAbdAb3gXtbEk87hsx9wAH0UKrqFhYKtkUnur36MOK+9RaIQSPOdA iE9EvzGyl0Ly4MK5U6f2dBh0YDJCUk0R0ITx8U5uy4JD3IuBKkRsHF8GB0Z22W4/phVeSk Cp7dK7KVTXJ7lGz0DGkh09NuAVLe5Xs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-252-Jahxg1_oOjKaLrJVe7kmLQ-1; Thu, 28 Mar 2024 04:32:46 -0400 X-MC-Unique: Jahxg1_oOjKaLrJVe7kmLQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0B332852000; Thu, 28 Mar 2024 08:32:46 +0000 (UTC) Received: from localhost (unknown [10.72.116.12]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4F752C01600; Thu, 28 Mar 2024 08:32:45 +0000 (UTC) Date: Thu, 28 Mar 2024 16:32:38 +0800 From: Baoquan He To: linux-mm@kvack.org Subject: Re: [PATCH v2 4/6] mm/mm_init.c: remove meaningless calculation of zone->managed_pages in free_area_init_core() Message-ID: References: <20240325145646.1044760-1-bhe@redhat.com> <20240325145646.1044760-5-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240325145646.1044760-5-bhe@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: akpm@linux-foundation.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, rppt@kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 03/25/24 at 10:56pm, Baoquan He wrote: > Currently, in free_area_init_core(), when initialize zone's field, a > rough value is set to zone->managed_pages. That value is calculated by > (zone->present_pages - memmap_pages). > > In the meantime, add the value to nr_all_pages and nr_kernel_pages which > represent all free pages of system (only low memory or including HIGHMEM > memory separately). Both of them are gonna be used in > alloc_large_system_hash(). > > However, the rough calculation and setting of zone->managed_pages is > meaningless because > a) memmap pages are allocated on units of node in sparse_init() or > alloc_node_mem_map(pgdat); The simple (zone->present_pages - > memmap_pages) is too rough to make sense for zone; > b) the set zone->managed_pages will be zeroed out and reset with > acutal value in mem_init() via memblock_free_all(). Before the > resetting, no buddy allocation request is issued. > > Here, remove the meaningless and complicated calculation of > (zone->present_pages - memmap_pages), initialize zone->managed_pages as 0 > which reflect its actual value because no any page is added into buddy > system right now. It will be reset in mem_init(). > > And also remove the assignment of nr_all_pages and nr_kernel_pages in > free_area_init_core(). Instead, call the newly added calc_nr_kernel_pages() > to count up all free but not reserved memory in memblock and assign to > nr_all_pages and nr_kernel_pages. The counting excludes memmap_pages, > and other kernel used data, which is more accurate than old way and > simpler, and can also cover the ppc required arch_reserved_kernel_pages() > case. > > And also clean up the outdated code comment above free_area_init_core(). > And free_area_init_core() is easy to understand now, no need to add > words to explain. > > Signed-off-by: Baoquan He > --- > mm/mm_init.c | 46 +++++----------------------------------------- > 1 file changed, 5 insertions(+), 41 deletions(-) > > diff --git a/mm/mm_init.c b/mm/mm_init.c > index c57a7fc97a16..7f71e56e83f3 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -1565,15 +1565,6 @@ void __ref free_area_init_core_hotplug(struct pglist_data *pgdat) > } > #endif > > -/* > - * Set up the zone data structures: > - * - mark all pages reserved > - * - mark all memory queues empty > - * - clear the memory bitmaps > - * > - * NOTE: pgdat should get zeroed by caller. > - * NOTE: this function is only called during early init. > - */ > static void __init free_area_init_core(struct pglist_data *pgdat) > { > enum zone_type j; > @@ -1584,41 +1575,13 @@ static void __init free_area_init_core(struct pglist_data *pgdat) > > for (j = 0; j < MAX_NR_ZONES; j++) { > struct zone *zone = pgdat->node_zones + j; > - unsigned long size, freesize, memmap_pages; > - > - size = zone->spanned_pages; > - freesize = zone->present_pages; > - > - /* > - * Adjust freesize so that it accounts for how much memory > - * is used by this zone for memmap. This affects the watermark > - * and per-cpu initialisations > - */ > - memmap_pages = calc_memmap_size(size, freesize); > - if (!is_highmem_idx(j)) { > - if (freesize >= memmap_pages) { > - freesize -= memmap_pages; > - if (memmap_pages) > - pr_debug(" %s zone: %lu pages used for memmap\n", > - zone_names[j], memmap_pages); > - } else > - pr_warn(" %s zone: %lu memmap pages exceeds freesize %lu\n", > - zone_names[j], memmap_pages, freesize); > - } > - > - if (!is_highmem_idx(j)) > - nr_kernel_pages += freesize; > - /* Charge for highmem memmap if there are enough kernel pages */ > - else if (nr_kernel_pages > memmap_pages * 2) > - nr_kernel_pages -= memmap_pages; > - nr_all_pages += freesize; > + unsigned long size = zone->spanned_pages; > > /* > - * Set an approximate value for lowmem here, it will be adjusted > - * when the bootmem allocator frees pages into the buddy system. > - * And all highmem pages will be managed by the buddy system. > + * Initialize zone->managed_pages as 0 , it will be reset > + * when memblock allocator frees pages into buddy system. > */ > - zone_init_internals(zone, j, nid, freesize); > + zone_init_internals(zone, j, nid, 0); Here, we should initialize zone->managed_pages as zone->present_pages because later page_group_by_mobility_disabled need be set according to zone->managed_pages. Otherwise page_group_by_mobility_disabled will be set to 1 always. I will sent out v3. >From a17b0921b4bd00596330f61ee9ea4b82386a9fed Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Thu, 28 Mar 2024 16:20:15 +0800 Subject: [PATCH] mm/mm_init.c: set zone's ->managed_pages as ->present_pages for now Content-type: text/plain Because page_group_by_mobility_disabled need be set according to zone's managed_pages later. Signed-off-by: Baoquan He --- mm/mm_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/mm_init.c b/mm/mm_init.c index cc24e7958c0c..dd875f943cbb 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -1561,7 +1561,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat) * Initialize zone->managed_pages as 0 , it will be reset * when memblock allocator frees pages into buddy system. */ - zone_init_internals(zone, j, nid, 0); + zone_init_internals(zone, j, nid, zone->present_pages); if (!size) continue; -- 2.41.0 > > if (!size) > continue; > @@ -1915,6 +1878,7 @@ void __init free_area_init(unsigned long *max_zone_pfn) > check_for_memory(pgdat); > } > > + calc_nr_kernel_pages(); > memmap_init(); > > /* disable hash distribution for systems with a single node */ > -- > 2.41.0 >