linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, linux-hyperv@vger.kernel.org,
	xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Matthew Wilcox <willy@infradead.org>,
	David Hildenbrand <david@redhat.com>,
	Wei Yang <richard.weiyang@linux.alibaba.com>,
	Michal Hocko <mhocko@suse.com>,
	Alexander Duyck <alexander.h.duyck@linux.intel.com>,
	Mel Gorman <mgorman@techsingularity.net>,
	Michal Hocko <mhocko@kernel.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Oscar Salvador <osalvador@suse.de>,
	Mike Rapoport <rppt@kernel.org>,
	Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Subject: [PATCH v2 5/5] mm/memory_hotplug: update comment regarding zone shuffling
Date: Mon,  5 Oct 2020 14:15:34 +0200	[thread overview]
Message-ID: <20201005121534.15649-6-david@redhat.com> (raw)
In-Reply-To: <20201005121534.15649-1-david@redhat.com>

As we no longer shuffle via generic_online_page() and when undoing
isolation, we can simplify the comment.

We now effectively shuffle only once (properly) when onlining new
memory.

Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 mm/memory_hotplug.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 03a00cb68bf7..b44d4c7ba73b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -858,13 +858,10 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
 	undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE);
 
 	/*
-	 * When exposing larger, physically contiguous memory areas to the
-	 * buddy, shuffling in the buddy (when freeing onlined pages, putting
-	 * them either to the head or the tail of the freelist) is only helpful
-	 * for maintaining the shuffle, but not for creating the initial
-	 * shuffle. Shuffle the whole zone to make sure the just onlined pages
-	 * are properly distributed across the whole freelist. Make sure to
-	 * shuffle once pageblocks are no longer isolated.
+	 * Freshly onlined pages aren't shuffled (e.g., all pages are placed to
+	 * the tail of the freelist when undoing isolation). Shuffle the whole
+	 * zone to make sure the just onlined pages are properly distributed
+	 * across the whole freelist - to create an initial shuffle.
 	 */
 	shuffle_zone(zone);
 
-- 
2.26.2



  parent reply	other threads:[~2020-10-05 12:16 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-05 12:15 [PATCH v2 0/5] mm: place pages to the freelist tail when onlining and undoing isolation David Hildenbrand
2020-10-05 12:15 ` [PATCH v2 1/5] mm/page_alloc: convert "report" flag of __free_one_page() to a proper flag David Hildenbrand
2020-10-05 12:15 ` [PATCH v2 2/5] mm/page_alloc: place pages to tail in __putback_isolated_page() David Hildenbrand
2020-10-20 17:18   ` Vlastimil Babka
2020-10-05 12:15 ` [PATCH v2 3/5] mm/page_alloc: move pages to tail in move_to_free_list() David Hildenbrand
2020-10-06 12:12   ` Michal Hocko
2020-10-20 17:20   ` Vlastimil Babka
2020-10-05 12:15 ` [PATCH v2 4/5] mm/page_alloc: place pages to tail in __free_pages_core() David Hildenbrand
2021-09-07 22:40   ` Sean Anderson
2021-09-08  6:21     ` David Hildenbrand
2021-09-10 23:06       ` Sean Anderson
2020-10-05 12:15 ` David Hildenbrand [this message]
2020-10-20 17:21   ` [PATCH v2 5/5] mm/memory_hotplug: update comment regarding zone shuffling Vlastimil Babka
2020-10-21 10:58   ` Pankaj Gupta

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=20201005121534.15649-6-david@redhat.com \
    --to=david@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=alexander.h.duyck@linux.intel.com \
    --cc=dave.hansen@intel.com \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@techsingularity.net \
    --cc=mhocko@kernel.org \
    --cc=mhocko@suse.com \
    --cc=osalvador@suse.de \
    --cc=pankaj.gupta.linux@gmail.com \
    --cc=richard.weiyang@linux.alibaba.com \
    --cc=rppt@kernel.org \
    --cc=vbabka@suse.cz \
    --cc=willy@infradead.org \
    --cc=xen-devel@lists.xenproject.org \
    --subject='Re: [PATCH v2 5/5] mm/memory_hotplug: update comment regarding zone shuffling' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).