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| author | Brice Goglin <Brice.Goglin@ens-lyon.org> | 2009-06-17 02:32:43 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-17 06:47:41 +0400 |
| commit | 35282a2de4e5e4e173ab61aa9d7015886021a821 (patch) | |
| tree | 06d20ad1a132e15e4fb7447cd9b139a4921ecfc9 /mm/migrate.c | |
| parent | 7f33d49a2ed546e01f7b1d0607661810f2421859 (diff) | |
| download | linux-35282a2de4e5e4e173ab61aa9d7015886021a821.tar.xz | |
migration: only migrate_prep() once per move_pages()
migrate_prep() is fairly expensive (72us on 16-core barcelona 1.9GHz).
Commit 3140a2273009c01c27d316f35ab76a37e105fdd8 improved move_pages()
throughput by breaking it into chunks, but it also made migrate_prep() be
called once per chunk (every 128pages or so) instead of once per
move_pages().
This patch reverts to calling migrate_prep() only once per chunk as we did
before 2.6.29. It is also a followup to commit
0aedadf91a70a11c4a3e7c7d99b21e5528af8d5d ("mm: move migrate_prep out from
under mmap_sem").
This improves migration throughput on the above machine from 600MB/s to
750MB/s.
Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 5a24923e7fd7..939888f9ddab 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -820,7 +820,6 @@ static int do_move_page_to_node_array(struct mm_struct *mm, struct page_to_node *pp; LIST_HEAD(pagelist); - migrate_prep(); down_read(&mm->mmap_sem); /* @@ -907,6 +906,9 @@ static int do_pages_move(struct mm_struct *mm, struct task_struct *task, pm = (struct page_to_node *)__get_free_page(GFP_KERNEL); if (!pm) goto out; + + migrate_prep(); + /* * Store a chunk of page_to_node array in a page, * but keep the last one as a marker |