From: Minchan Kim <minchan@kernel.org>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Mel Gorman <mgorman@suse.de>,
Andrea Arcangeli <aarcange@redhat.com>,
Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH] THP: Use explicit memory barrier
Date: Tue, 2 Apr 2013 09:37:46 +0900 [thread overview]
Message-ID: <20130402003746.GA30444@blaptop> (raw)
In-Reply-To: <alpine.DEB.2.02.1304011634530.21603@chino.kir.corp.google.com>
On Mon, Apr 01, 2013 at 04:35:38PM -0700, David Rientjes wrote:
> On Mon, 1 Apr 2013, Minchan Kim wrote:
>
> > __do_huge_pmd_anonymous_page depends on page_add_new_anon_rmap's
> > spinlock for making sure that clear_huge_page write become visible
> > after set set_pmd_at() write.
> >
> > But lru_cache_add_lru uses pagevec so it could miss spinlock
> > easily so above rule was broken so user may see inconsistent data.
> >
> > This patch fixes it with using explict barrier rather than depending
> > on lru spinlock.
> >
>
> Is this the same issue that Andrea responded to in the "thp and memory
> barrier assumptions" thread at http://marc.info/?t=134333512700004 ?
Yes and Peter pointed out further step.
Thanks for pointing out.
Not that I know that Andrea alreay noticed it, I don't care about this
patch.
Remaining question is Kame's one.
Isn't there anyone could answer it?
>
> --
> 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>
--
Kind regards,
Minchan Kim
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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WARNING: multiple messages have this Message-ID (diff)
From: Minchan Kim <minchan@kernel.org>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Mel Gorman <mgorman@suse.de>,
Andrea Arcangeli <aarcange@redhat.com>,
Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH] THP: Use explicit memory barrier
Date: Tue, 2 Apr 2013 09:37:46 +0900 [thread overview]
Message-ID: <20130402003746.GA30444@blaptop> (raw)
In-Reply-To: <alpine.DEB.2.02.1304011634530.21603@chino.kir.corp.google.com>
On Mon, Apr 01, 2013 at 04:35:38PM -0700, David Rientjes wrote:
> On Mon, 1 Apr 2013, Minchan Kim wrote:
>
> > __do_huge_pmd_anonymous_page depends on page_add_new_anon_rmap's
> > spinlock for making sure that clear_huge_page write become visible
> > after set set_pmd_at() write.
> >
> > But lru_cache_add_lru uses pagevec so it could miss spinlock
> > easily so above rule was broken so user may see inconsistent data.
> >
> > This patch fixes it with using explict barrier rather than depending
> > on lru spinlock.
> >
>
> Is this the same issue that Andrea responded to in the "thp and memory
> barrier assumptions" thread at http://marc.info/?t=134333512700004 ?
Yes and Peter pointed out further step.
Thanks for pointing out.
Not that I know that Andrea alreay noticed it, I don't care about this
patch.
Remaining question is Kame's one.
Isn't there anyone could answer it?
>
> --
> 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>
--
Kind regards,
Minchan Kim
next prev parent reply other threads:[~2013-04-02 0:37 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-31 23:45 [PATCH] THP: Use explicit memory barrier Minchan Kim
2013-03-31 23:45 ` Minchan Kim
2013-04-01 1:01 ` Kamezawa Hiroyuki
2013-04-01 1:01 ` Kamezawa Hiroyuki
2013-04-01 4:45 ` Minchan Kim
2013-04-01 4:45 ` Minchan Kim
2013-04-01 23:35 ` David Rientjes
2013-04-01 23:35 ` David Rientjes
2013-04-02 0:37 ` Minchan Kim [this message]
2013-04-02 0:37 ` Minchan Kim
2013-04-02 19:20 ` David Rientjes
2013-04-02 19:20 ` David Rientjes
2013-04-02 19:30 ` Hugh Dickins
2013-04-02 19:30 ` Hugh Dickins
2013-04-03 0:14 ` Minchan Kim
2013-04-03 0:14 ` Minchan Kim
2013-04-04 13:45 ` Andrea Arcangeli
2013-04-04 13:45 ` Andrea Arcangeli
2013-04-04 2:45 ` Simon Jeons
2013-04-04 2:45 ` Simon Jeons
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