From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Dave Jones <davej@redhat.com>,
Darren Hart <dvhart@linux.intel.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Mel Gorman <mgorman@suse.de>,
Heiko Carstens <heiko.carstens@de.ibm.com>
Subject: Re: [PATCH 0/1] mm: fix the theoretical compound_lock() vs prep_new_page() race
Date: Fri, 20 Dec 2013 15:19:17 +0100 [thread overview]
Message-ID: <20131220151917.54309071@mschwide> (raw)
In-Reply-To: <20131219190846.GA24566@redhat.com>
On Thu, 19 Dec 2013 20:08:46 +0100
Oleg Nesterov <oleg@redhat.com> wrote:
> On 12/16, Andrea Arcangeli wrote:
> >
> > Can you reorder set_page_refcount in your v2?
>
> Please see the patch.
>
> > I wonder if arch_alloc_page needs refcount 1, it sets the page as
> > stable on s390.
>
> Obviously I have no idea what set_page_stable() does, but it works
> with page_to_phys(), unlikely the content of "struct page" can matter.
> And only s390 HAVE_ARCH_ALLOC_PAGE, I added Martin and Heiko.
On s390 the arch_alloc_page primitive is used to tell the hipervisor
that a page is going to be used. While the page is free it is marked
as "unused" which allows the hipervisor to throw away the page content
if the page is selected to be swapped. We do have a patch to add the
host support for KVM somewhere in our queue.
The content of the "struct page" does not matter at all for the
set-stable/set-unused state transition, s390 does not care about
the refcount in its arch_alloc_page function.
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
next prev parent reply other threads:[~2013-12-20 14:19 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-10 15:47 process 'stuck' at exit Dave Jones
2013-12-10 18:40 ` Linus Torvalds
2013-12-10 19:18 ` Thomas Gleixner
2013-12-10 19:55 ` Linus Torvalds
2013-12-10 20:27 ` Dave Jones
2013-12-10 20:34 ` Thomas Gleixner
2013-12-10 20:55 ` Dave Jones
2013-12-10 21:25 ` Darren Hart
2013-12-10 21:28 ` Thomas Gleixner
2013-12-10 21:39 ` Steven Rostedt
2013-12-10 20:33 ` Thomas Gleixner
2013-12-10 20:43 ` Linus Torvalds
2013-12-10 21:17 ` Thomas Gleixner
2013-12-10 20:35 ` Oleg Nesterov
2013-12-10 20:49 ` Dave Jones
2013-12-10 21:06 ` Darren Hart
2013-12-10 21:12 ` Dave Jones
2013-12-10 21:18 ` Linus Torvalds
2013-12-10 21:24 ` Linus Torvalds
2013-12-10 21:32 ` Dave Jones
2013-12-10 21:49 ` Linus Torvalds
2013-12-10 21:56 ` Dave Jones
2013-12-10 21:59 ` Linus Torvalds
2013-12-10 22:07 ` Dave Jones
2013-12-11 12:45 ` Ingo Molnar
2013-12-10 21:34 ` Oleg Nesterov
2013-12-10 21:41 ` Dave Jones
2013-12-10 21:57 ` Linus Torvalds
2013-12-10 22:02 ` Dave Jones
2013-12-10 22:09 ` Oleg Nesterov
2013-12-10 22:19 ` Linus Torvalds
2013-12-10 22:33 ` Linus Torvalds
2013-12-10 22:38 ` Darren Hart
2013-12-10 22:57 ` Thomas Gleixner
2013-12-10 23:05 ` Linus Torvalds
2013-12-10 23:28 ` Thomas Gleixner
2013-12-10 23:31 ` Al Viro
2013-12-11 17:08 ` Oleg Nesterov
2013-12-11 17:18 ` Thomas Gleixner
2013-12-11 17:56 ` Oleg Nesterov
2013-12-11 19:18 ` PATCH? introduce get_compound_page (Was: process 'stuck' at exit) Oleg Nesterov
2013-12-13 15:10 ` Andrea Arcangeli
2013-12-13 16:22 ` Oleg Nesterov
2013-12-13 17:34 ` Andrea Arcangeli
2013-12-16 18:36 ` Oleg Nesterov
2013-12-16 20:19 ` Andrea Arcangeli
2013-12-16 20:46 ` Oleg Nesterov
2013-12-17 16:53 ` Oleg Nesterov
2013-12-17 18:06 ` Andrea Arcangeli
2013-12-18 19:19 ` [PATCH -mm 0/7] (Was: introduce get_compound_page) Oleg Nesterov
2013-12-18 19:19 ` [PATCH -mm 1/7] mm: thp: introduce __put_nontail_page() Oleg Nesterov
2013-12-18 19:19 ` [PATCH -mm 2/7] mm: thp: change __get_page_tail() to use __put_nontail_page() Oleg Nesterov
2013-12-18 19:19 ` [PATCH -mm 3/7] mm: change release_pages() to use put_page() rather than put_compound_page() Oleg Nesterov
2013-12-18 19:19 ` [PATCH -mm 4/7] mm: thp: turn put_compound_page() into __put_page_tail() Oleg Nesterov
2013-12-18 19:36 ` Peter Zijlstra
2013-12-18 19:50 ` Oleg Nesterov
2013-12-18 19:20 ` [PATCH -mm 5/7] mm: thp: reorganize out_put_single code in __put_page_tail() Oleg Nesterov
2013-12-18 19:20 ` [PATCH -mm 6/7] mm: thp: introduce get_lock_thp_head() Oleg Nesterov
2013-12-18 21:37 ` Linus Torvalds
2013-12-19 16:29 ` Oleg Nesterov
2013-12-18 19:20 ` [PATCH -mm 7/7] mm: thp: introduce compound_head_put_tail(), change get_futex_key() to use it Oleg Nesterov
2013-12-18 19:28 ` Peter Zijlstra
2013-12-18 19:40 ` Oleg Nesterov
2013-12-19 19:08 ` [PATCH 0/1] mm: fix the theoretical compound_lock() vs prep_new_page() race Oleg Nesterov
2013-12-19 19:09 ` [PATCH 1/1] " Oleg Nesterov
2013-12-23 11:43 ` Andrea Arcangeli
2014-01-03 19:55 ` [PATCH v2 0/1] " Oleg Nesterov
2014-01-03 19:55 ` [PATCH v2 1/1] " Oleg Nesterov
2014-01-03 21:00 ` Andrew Morton
2014-01-04 16:43 ` Oleg Nesterov
2014-01-08 11:54 ` Mel Gorman
2014-01-08 13:14 ` Mel Gorman
2014-01-08 16:13 ` Oleg Nesterov
2014-01-08 18:02 ` Mel Gorman
2014-01-08 19:04 ` Oleg Nesterov
2014-01-09 11:27 ` Mel Gorman
2014-01-09 14:04 ` Oleg Nesterov
2014-01-09 18:52 ` Andrea Arcangeli
2014-01-09 19:43 ` Oleg Nesterov
2014-01-09 21:36 ` Andrea Arcangeli
2014-01-10 16:12 ` Oleg Nesterov
2014-01-10 16:50 ` Peter Zijlstra
2014-01-10 16:12 ` Mel Gorman
2013-12-20 14:19 ` Martin Schwidefsky [this message]
2013-12-16 20:19 ` [PATCH 0/2] mm: thp: get_huge_page_tail() cleanups Oleg Nesterov
2013-12-16 20:19 ` [PATCH -mm 1/2] mm: thp: __get_page_tail_foll() can use get_huge_page_tail() Oleg Nesterov
2013-12-16 20:19 ` [PATCH -mm 2/2] mm: thp: turn compound_head() into BUG_ON(!PageTail) in get_huge_page_tail() Oleg Nesterov
2013-12-16 20:27 ` [PATCH 0/2] mm: thp: get_huge_page_tail() cleanups Andrea Arcangeli
2013-12-10 22:42 ` process 'stuck' at exit Thomas Gleixner
2013-12-10 22:48 ` Linus Torvalds
2013-12-10 22:58 ` Darren Hart
2013-12-10 23:01 ` Dave Jones
2013-12-10 23:00 ` Dave Jones
2013-12-11 0:05 ` Steven Rostedt
2013-12-11 0:23 ` Dave Jones
2013-12-11 0:55 ` Dave Jones
2013-12-14 20:17 ` Oleg Nesterov
2013-12-11 4:09 ` Dave Jones
2013-12-12 4:26 ` Dave Jones
2013-12-12 5:29 ` Darren Hart
2013-12-10 22:51 ` Darren Hart
2013-12-10 23:24 ` Al Viro
2013-12-11 16:31 ` Mel Gorman
2013-12-11 16:38 ` Thomas Gleixner
2013-12-11 17:57 ` Mel Gorman
2013-12-12 19:00 ` Andrea Arcangeli
2013-12-12 19:03 ` Linus Torvalds
2013-12-10 22:09 ` Steven Rostedt
2013-12-10 22:16 ` Dave Jones
2013-12-10 22:21 ` Steven Rostedt
2013-12-10 22:27 ` Dave Jones
2013-12-11 1:02 ` Mel Gorman
2013-12-10 20:57 ` Darren Hart
2013-12-10 21:09 ` Dave Jones
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