From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Hugh Dickins <hughd@google.com>,
"hannes@cmpxchg.org" <hannes@cmpxchg.org>
Subject: Re: [PATCH RFC 00/15] mm: memory book keeping and lru_lock splitting
Date: Thu, 16 Feb 2012 17:24:09 +0900 [thread overview]
Message-ID: <20120216172409.5fa18608.kamezawa.hiroyu@jp.fujitsu.com> (raw)
In-Reply-To: <4F3C9798.7050800@openvz.org>
On Thu, 16 Feb 2012 09:43:52 +0400
Konstantin Khlebnikov <khlebnikov@openvz.org> wrote:
> KAMEZAWA Hiroyuki wrote:
> > On Thu, 16 Feb 2012 02:57:04 +0400
> > Konstantin Khlebnikov<khlebnikov@openvz.org> wrote:
> >> * optimize page to book translations, move it upper in the call stack,
> >> replace some struct zone arguments with struct book pointer.
> >>
> >
> > a page->book transrater from patch 2/15
> >
> > +struct book *page_book(struct page *page)
> > +{
> > + struct mem_cgroup_per_zone *mz;
> > + struct page_cgroup *pc;
> > +
> > + if (mem_cgroup_disabled())
> > + return&page_zone(page)->book;
> > +
> > + pc = lookup_page_cgroup(page);
> > + if (!PageCgroupUsed(pc))
> > + return&page_zone(page)->book;
> > + /* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
> > + smp_rmb();
> > + mz = mem_cgroup_zoneinfo(pc->mem_cgroup,
> > + page_to_nid(page), page_zonenum(page));
> > + return&mz->book;
> > +}
> >
> > What happens when pc->mem_cgroup is rewritten by move_account() ?
> > Where is the guard for lockless access of this ?
>
> Initially this suppose to be protected with lru_lock, in final patch they are protected with rcu.
Hmm, VM_BUG_ON(!PageLRU(page)) ?
move_account() overwrites pc->mem_cgroup with isolating page from LRU.
but it doesn't take lru_lock.
BTW, what amount of perfomance benefit ?
Thanks,
-Kame
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next prev parent reply other threads:[~2012-02-16 8:25 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-15 22:57 Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 01/15] mm: rename struct lruvec into struct book Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 02/15] mm: memory bookkeeping core Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 03/15] mm: add book->pages_count Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 04/15] mm: unify inactive_list_is_low() Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 05/15] mm: add book->reclaim_stat Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 06/15] mm: kill struct mem_cgroup_zone Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 07/15] mm: move page-to-book translation upper Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 08/15] mm: introduce book locking primitives Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 09/15] mm: handle book relocks on lumpy reclaim Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 10/15] mm: handle book relocks in compaction Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 11/15] mm: handle book relock in memory controller Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 12/15] mm: optimize books in update_page_reclaim_stat() Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 13/15] mm: optimize books in pagevec_lru_move_fn() Konstantin Khlebnikov
2012-02-15 22:57 ` [PATCH RFC 14/15] mm: optimize putback for 0-order reclaim Konstantin Khlebnikov
2012-02-15 22:58 ` [PATCH RFC 15/15] mm: split zone->lru_lock Konstantin Khlebnikov
2012-02-16 2:04 ` [PATCH RFC 00/15] mm: memory book keeping and lru_lock splitting KAMEZAWA Hiroyuki
2012-02-16 5:43 ` Konstantin Khlebnikov
2012-02-16 8:24 ` KAMEZAWA Hiroyuki [this message]
2012-02-16 11:02 ` Konstantin Khlebnikov
2012-02-16 15:54 ` Konstantin Khlebnikov
2012-02-16 23:54 ` KAMEZAWA Hiroyuki
2012-02-18 9:09 ` Konstantin Khlebnikov
2012-02-16 2:37 ` Hugh Dickins
2012-02-16 4:51 ` Konstantin Khlebnikov
2012-02-16 21:37 ` Hugh Dickins
2012-02-17 19:56 ` Konstantin Khlebnikov
2012-02-18 2:13 ` Hugh Dickins
2012-02-18 6:35 ` Konstantin Khlebnikov
2012-02-18 7:14 ` Hugh Dickins
2012-02-20 0:32 ` KAMEZAWA Hiroyuki
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