From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> To: Brice Goglin <Brice.Goglin@ens-lyon.org> Cc: Christoph Lameter <cl@linux-foundation.org>, linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] migration: only migrate_prep() once per move_pages() Date: Wed, 15 Apr 2009 16:49:55 +0900 [thread overview] Message-ID: <20090415164955.41746866.kamezawa.hiroyu@jp.fujitsu.com> (raw) In-Reply-To: <49E58D7A.4010708@ens-lyon.org> On Wed, 15 Apr 2009 09:32:10 +0200 Brice Goglin <Brice.Goglin@ens-lyon.org> wrote: > 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> > Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> I think this patch is good. page migration is best-effort syscall ;) BTW, current users of sys_move_pages() does retry when it gets -EBUSY ? Thanks, -Kame > diff --git a/mm/migrate.c b/mm/migrate.c > index 068655d..a2d3e83 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 > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> >
WARNING: multiple messages have this Message-ID (diff)
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> To: Brice Goglin <Brice.Goglin@ens-lyon.org> Cc: Christoph Lameter <cl@linux-foundation.org>, linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] migration: only migrate_prep() once per move_pages() Date: Wed, 15 Apr 2009 16:49:55 +0900 [thread overview] Message-ID: <20090415164955.41746866.kamezawa.hiroyu@jp.fujitsu.com> (raw) In-Reply-To: <49E58D7A.4010708@ens-lyon.org> On Wed, 15 Apr 2009 09:32:10 +0200 Brice Goglin <Brice.Goglin@ens-lyon.org> wrote: > 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> > Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> I think this patch is good. page migration is best-effort syscall ;) BTW, current users of sys_move_pages() does retry when it gets -EBUSY ? Thanks, -Kame > diff --git a/mm/migrate.c b/mm/migrate.c > index 068655d..a2d3e83 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 > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2009-04-15 7:51 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2009-04-15 7:32 [PATCH] migration: only migrate_prep() once per move_pages() Brice Goglin 2009-04-15 7:32 ` Brice Goglin 2009-04-15 7:49 ` KAMEZAWA Hiroyuki [this message] 2009-04-15 7:49 ` KAMEZAWA Hiroyuki 2009-04-15 9:33 ` Brice Goglin 2009-04-15 9:33 ` Brice Goglin 2009-04-15 12:41 ` Christoph Lameter 2009-04-15 12:41 ` Christoph Lameter 2009-05-13 5:52 ` Brice Goglin 2009-05-13 5:52 ` Brice Goglin 2009-05-14 20:11 ` Christoph Lameter 2009-05-14 20:11 ` Christoph Lameter
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