All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oscar Salvador <osalvador@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>,
	Michal Hocko <mhocko@kernel.org>,
	Wei Yang <richard.weiyang@gmail.com>,
	Miaohe Lin <linmiaohe@huawei.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Oscar Salvador <osalvador@suse.de>
Subject: [PATCH 1/3] mm/page_alloc: Do not calculate node's total pages and memmap pages when empty
Date: Mon,  7 Mar 2022 16:07:23 +0100	[thread overview]
Message-ID: <20220307150725.6810-2-osalvador@suse.de> (raw)
In-Reply-To: <20220307150725.6810-1-osalvador@suse.de>

free_area_init_node() calls calculate_node_totalpages() and
free_area_init_core(). The former to get node's {spanned,present}_pages,
and the latter to calculate, among other things, how many pages per zone
we spent on memmap_pages, which is used to substract zone's free pages.

On memoryless-nodes, it is pointless to perform such a bunch of work, so
make sure we skip the calculations when having a node or empty zone.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 mm/page_alloc.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 967085c1c78a..0b7d176a8990 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7312,6 +7312,10 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
 	unsigned long realtotalpages = 0, totalpages = 0;
 	enum zone_type i;
 
+	/* Skip calculation for memoryless nodes */
+	if (node_start_pfn == node_end_pfn)
+		goto no_pages;
+
 	for (i = 0; i < MAX_NR_ZONES; i++) {
 		struct zone *zone = pgdat->node_zones + i;
 		unsigned long zone_start_pfn, zone_end_pfn;
@@ -7344,6 +7348,7 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
 		realtotalpages += real_size;
 	}
 
+no_pages:
 	pgdat->node_spanned_pages = totalpages;
 	pgdat->node_present_pages = realtotalpages;
 	pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
@@ -7562,6 +7567,10 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
 		size = zone->spanned_pages;
 		freesize = zone->present_pages;
 
+		/* No pages? Nothing to calculate then. */
+		if (!size)
+			goto no_pages;
+
 		/*
 		 * Adjust freesize so that it accounts for how much memory
 		 * is used by this zone for memmap. This affects the watermark
@@ -7597,6 +7606,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
 		 * when the bootmem allocator frees pages into the buddy system.
 		 * And all highmem pages will be managed by the buddy system.
 		 */
+no_pages:
 		zone_init_internals(zone, j, nid, freesize);
 
 		if (!size)
-- 
2.34.1


  reply	other threads:[~2022-03-07 15:07 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-07 15:07 [PATCH 0/3] A minor hotplug refactoring Oscar Salvador
2022-03-07 15:07 ` Oscar Salvador [this message]
2022-04-28 12:13   ` [PATCH 1/3] mm/page_alloc: Do not calculate node's total pages and memmap pages when empty David Hildenbrand
2022-05-05  9:09     ` Oscar Salvador
2022-03-07 15:07 ` [PATCH 2/3] mm/memory_hotplug: Reset node's state when empty during offline Oscar Salvador
2022-04-28 12:30   ` David Hildenbrand
2022-05-05 10:37     ` Oscar Salvador
2022-03-07 15:07 ` [PATCH 3/3] mm/memory_hotplug: Refactor hotadd_init_pgdat and try_online_node Oscar Salvador
2022-04-28 12:35   ` David Hildenbrand
2022-05-05  9:17     ` Oscar Salvador
2022-04-27 21:05 ` [PATCH 0/3] A minor hotplug refactoring Andrew Morton

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220307150725.6810-2-osalvador@suse.de \
    --to=osalvador@suse.de \
    --cc=akpm@linux-foundation.org \
    --cc=david@redhat.com \
    --cc=linmiaohe@huawei.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=richard.weiyang@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.