From: Linus Torvalds <torvalds@linux-foundation.org>
To: Christoph Lameter <clameter@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <andrea@qumranet.com>,
steiner@sgi.com, holt@sgi.com, npiggin@suse.de,
a.p.zijlstra@chello.nl, kvm-devel@lists.sourceforge.net,
kanojsarcar@yahoo.com, rdreier@cisco.com,
swise@opengridcomputing.com, linux-kernel@vger.kernel.org,
avi@qumranet.com, linux-mm@kvack.org,
general@lists.openfabrics.org, hugh@veritas.com,
rusty@rustcorp.com.au, aliguori@us.ibm.com, chrisw@redhat.com,
marcelo@kvack.org, dada1@cosmosbay.com, paulmck@us.ibm.com
Subject: Re: [PATCH 08 of 11] anon-vma-rwsem
Date: Wed, 7 May 2008 17:03:30 -0700 (PDT) [thread overview]
Message-ID: <alpine.LFD.1.10.0805071655100.3024@woody.linux-foundation.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0805071637360.14337@schroedinger.engr.sgi.com>
On Wed, 7 May 2008, Christoph Lameter wrote:
>
> Multiple vmas may share the same mapping or refer to the same anonymous
> vma. The above code will deadlock since we may take some locks multiple
> times.
Ok, so that actually _is_ a problem. It would be easy enough to also add
just a flag to the vma (VM_MULTILOCKED), which is still cleaner than doing
a vmalloc and a whole sort thing, but if this is really rare, maybe Ben's
suggestion of just using stop-machine is actually the right one just
because it's _so_ simple.
(That said, we're not running out of vm flags yet, and if we were, we
could just add another word. We're already wasting that space right now on
64-bit by calling it "unsigned long").
Linus
next prev parent reply other threads:[~2008-05-08 0:10 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-07 14:35 [PATCH 00 of 11] mmu notifier #v16 Andrea Arcangeli
2008-05-07 14:35 ` [PATCH 01 of 11] mmu-notifier-core Andrea Arcangeli
2008-05-07 17:35 ` Rik van Riel
2008-05-07 20:02 ` Andrew Morton
2008-05-07 20:05 ` Andrew Morton
2008-05-07 20:30 ` Linus Torvalds
2008-05-07 21:58 ` Andrea Arcangeli
2008-05-07 22:11 ` Linus Torvalds
2008-05-07 22:27 ` Andrea Arcangeli
2008-05-07 22:31 ` [ofa-general] " Roland Dreier
2008-05-07 22:39 ` Andrea Arcangeli
2008-05-07 23:03 ` Linus Torvalds
2008-05-07 22:37 ` Andrea Arcangeli
2008-05-07 23:38 ` Linus Torvalds
2008-05-07 23:00 ` Linus Torvalds
2008-05-07 14:35 ` [PATCH 02 of 11] get_task_mm Andrea Arcangeli
2008-05-07 15:59 ` Robin Holt
2008-05-07 16:20 ` Andrea Arcangeli
2008-05-07 14:35 ` [PATCH 03 of 11] invalidate_page outside PT lock Andrea Arcangeli
2008-05-07 17:39 ` Rik van Riel
2008-05-07 17:57 ` Andrea Arcangeli
2008-05-07 14:35 ` [PATCH 04 of 11] free-pgtables Andrea Arcangeli
2008-05-07 17:41 ` Rik van Riel
2008-05-07 14:35 ` [PATCH 05 of 11] unmap vmas tlb flushing Andrea Arcangeli
2008-05-07 17:46 ` Rik van Riel
2008-05-07 14:35 ` [PATCH 06 of 11] rwsem contended Andrea Arcangeli
2008-05-07 14:35 ` [PATCH 07 of 11] i_mmap_rwsem Andrea Arcangeli
2008-05-07 14:35 ` [PATCH 08 of 11] anon-vma-rwsem Andrea Arcangeli
2008-05-07 20:56 ` Linus Torvalds
2008-05-07 21:26 ` Andrea Arcangeli
2008-05-07 21:36 ` Linus Torvalds
2008-05-07 22:22 ` Andrea Arcangeli
2008-05-07 22:31 ` Andrew Morton
2008-05-07 22:44 ` Andrea Arcangeli
2008-05-07 22:59 ` Andrew Morton
2008-05-07 23:19 ` Linus Torvalds
2008-05-07 23:39 ` Christoph Lameter
2008-05-08 0:03 ` Linus Torvalds [this message]
2008-05-08 0:52 ` Robin Holt
2008-05-08 0:56 ` Christoph Lameter
2008-05-08 1:07 ` Linus Torvalds
2008-05-08 1:39 ` Linus Torvalds
2008-05-08 1:52 ` Andrea Arcangeli
2008-05-08 1:57 ` Linus Torvalds
2008-05-08 2:24 ` Andrea Arcangeli
2008-05-08 2:32 ` Linus Torvalds
2008-05-07 23:39 ` Andrea Arcangeli
2008-05-08 1:02 ` Linus Torvalds
2008-05-08 1:12 ` Christoph Lameter
2008-05-08 1:32 ` Linus Torvalds
2008-05-08 2:56 ` Andrea Arcangeli
2008-05-08 3:10 ` Christoph Lameter
2008-05-08 3:41 ` Andrea Arcangeli
2008-05-08 4:14 ` Linus Torvalds
2008-05-08 5:20 ` Andrea Arcangeli
2008-05-08 5:27 ` Pekka Enberg
2008-05-08 5:30 ` Pekka Enberg
2008-05-08 5:49 ` Andrea Arcangeli
2008-05-08 15:03 ` Linus Torvalds
2008-05-08 16:11 ` Linus Torvalds
2008-05-08 22:01 ` Andrea Arcangeli
2008-05-09 18:37 ` Peter Zijlstra
2008-05-09 18:55 ` Andrea Arcangeli
2008-05-09 19:04 ` Peter Zijlstra
2008-05-08 1:26 ` Andrea Arcangeli
2008-05-07 23:28 ` Benjamin Herrenschmidt
2008-05-07 23:45 ` Andrea Arcangeli
2008-05-08 1:34 ` Andrea Arcangeli
2008-05-13 12:14 ` Nick Piggin
2008-05-14 5:43 ` Benjamin Herrenschmidt
2008-05-14 6:06 ` Nick Piggin
2008-05-14 13:15 ` Jack Steiner
2008-05-07 22:44 ` Linus Torvalds
2008-05-07 22:58 ` Andrea Arcangeli
2008-05-07 23:02 ` Andrea Arcangeli
2008-05-07 23:09 ` Linus Torvalds
2008-05-08 0:38 ` Robin Holt
2008-05-08 0:55 ` Linus Torvalds
2008-05-13 12:06 ` Nick Piggin
2008-05-13 15:32 ` Robin Holt
2008-05-14 4:11 ` Nick Piggin
2008-05-14 11:26 ` Robin Holt
2008-05-14 15:18 ` Linus Torvalds
2008-05-14 16:22 ` Robin Holt
2008-05-14 16:56 ` Linus Torvalds
2008-05-14 17:57 ` Christoph Lameter
2008-05-14 18:27 ` Linus Torvalds
2008-05-17 1:38 ` mm notifier: Notifications when pages are unmapped Christoph Lameter
2008-05-15 7:57 ` [PATCH 08 of 11] anon-vma-rwsem Nick Piggin
2008-05-15 11:01 ` Robin Holt
2008-05-15 11:12 ` Avi Kivity
2008-05-15 17:33 ` Christoph Lameter
2008-05-15 23:52 ` Nick Piggin
2008-05-16 11:23 ` Robin Holt
2008-05-16 11:50 ` Robin Holt
2008-05-20 5:31 ` Nick Piggin
2008-05-20 10:01 ` Robin Holt
2008-05-20 10:50 ` Nick Piggin
2008-05-20 11:05 ` Robin Holt
2008-05-20 11:14 ` Nick Piggin
2008-05-20 11:26 ` Robin Holt
2008-05-07 22:42 ` Jack Steiner
2008-05-07 14:35 ` [PATCH 09 of 11] mm_lock-rwsem Andrea Arcangeli
2008-05-07 14:36 ` [PATCH 10 of 11] export zap_page_range for XPMEM Andrea Arcangeli
2008-05-07 14:36 ` [PATCH 11 of 11] mmap sems Andrea Arcangeli
-- strict thread matches above, loose matches on Subject: below --
2008-05-02 15:05 [PATCH 00 of 11] mmu notifier #v15 Andrea Arcangeli
2008-05-02 15:05 ` [PATCH 08 of 11] anon-vma-rwsem Andrea Arcangeli
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