From: Andrew Morton <akpm@zip.com.au>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: Rik van Riel <riel@conectiva.com.br>,
Andrea Arcangeli <andrea@suse.de>,
Momchil Velikov <velco@fadata.bg>,
John Stoffel <stoffel@casc.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Radix-tree pagecache for 2.5
Date: Thu, 31 Jan 2002 11:26:37 -0800 [thread overview]
Message-ID: <3C599A6B.98724FD1@zip.com.au> (raw)
In-Reply-To: <Pine.LNX.4.33L.0201311635290.32634-100000@imladris.surriel.com> <Pine.LNX.4.33.0201311047200.1682-100000@penguin.transmeta.com>
Linus Torvalds wrote:
>
> On Thu, 31 Jan 2002, Rik van Riel wrote:
> >
> > It's still a question whether we'll want to use 128 as
> > the branch factor or another number ... but I'm sure
> > somebody will figure that out (and it can be changed
> > later, it's just one define).
>
> Actually, I think the big question is whether somebody is willing to clean
> up and fix the "move_from_swap_cache()" issue with block_flushpage.
>
It appears that move_from_swap_cache() is in good company:
1: shmem_unuse_inode() calls delete_from_swap_cache under
spinlock, but delete_from_swap_cache() calls block_flushpage(),
which can sleep.
2: shmem_getpage_locked() calls delete_from_swap_cache() calls
block_flushpage() under info->lock.
3: zap_pte_range holds mm->page_table_lock, and calls
free_swap_and_cache() calls delete_from_swap_cache() calls
block_flushpage().
block_flushpage() can only sleep in the lock_buffer() in
discard_buffer(). It so happens that all three callers
are always using block_flushpage() against a locked
swapcache page, and (correct me if I'm wrong), it's
not possible for those buffers to be locked.
So we got lucky.
A short-term fix is to put a BIG FAT COMMENT over block_flushpage.
-
next prev parent reply other threads:[~2002-01-31 19:34 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-01-29 15:54 [PATCH] Radix-tree pagecache for 2.5 Christoph Hellwig
2002-01-29 19:27 ` Linus Torvalds
2002-01-29 21:40 ` David S. Miller
2002-01-29 22:07 ` Linus Torvalds
2002-01-29 23:01 ` Rik van Riel
2002-01-29 23:32 ` Alan Cox
2002-01-29 23:35 ` Rik van Riel
2002-01-30 3:00 ` Daniel Phillips
2002-01-31 23:44 ` Anton Blanchard
2002-02-01 0:34 ` Alan Cox
2002-02-01 11:04 ` Rik van Riel
2002-02-01 11:33 ` Arjan van de Ven
2002-02-02 18:57 ` Richard Henderson
2002-02-02 21:15 ` Rik van Riel
2002-01-29 23:02 ` Momchil Velikov
2002-01-29 23:33 ` Linus Torvalds
2002-01-29 23:45 ` Christoph Hellwig
2002-01-30 21:25 ` Momchil Velikov
2002-01-30 22:05 ` John Stoffel
2002-01-30 22:15 ` Momchil Velikov
2002-01-31 2:33 ` Andrea Arcangeli
2002-01-31 13:58 ` Rik van Riel
2002-01-31 14:36 ` Andrea Arcangeli
2002-01-31 15:32 ` Alan Cox
2002-01-31 16:39 ` William Lee Irwin III
2002-01-31 17:19 ` William Lee Irwin III
2002-01-31 17:21 ` Andrea Arcangeli
2002-01-31 17:50 ` William Lee Irwin III
2002-01-31 17:46 ` Linus Torvalds
2002-01-31 18:02 ` Andrea Arcangeli
2002-01-31 18:32 ` Linus Torvalds
2002-01-31 18:38 ` Rik van Riel
2002-01-31 18:49 ` Linus Torvalds
2002-01-31 19:09 ` Momchil Velikov
2002-01-31 19:26 ` Andrew Morton [this message]
2002-01-31 21:12 ` Momchil Velikov
2002-01-31 19:14 ` Andrea Arcangeli
2002-01-31 19:23 ` Linus Torvalds
2002-01-31 21:34 ` Ingo Molnar
2002-01-31 23:12 ` Anton Blanchard
2002-01-31 23:55 ` Andrea Arcangeli
2002-02-01 0:01 ` David S. Miller
2002-02-16 16:20 ` Andrea Arcangeli
2002-02-01 3:56 ` Anton Blanchard
2002-02-01 6:32 ` Momchil Velikov
2002-02-01 18:38 ` Anton Blanchard
2002-02-01 9:04 ` Ingo Molnar
2002-02-01 7:59 ` Momchil Velikov
2002-02-01 10:29 ` Ingo Molnar
2002-02-01 9:01 ` Momchil Velikov
2002-02-01 9:10 ` David S. Miller
2002-02-01 9:07 ` David S. Miller
2002-02-01 9:13 ` Momchil Velikov
2002-02-01 17:06 ` Linus Torvalds
2002-02-01 18:29 ` Jeff Garzik
2002-02-01 18:44 ` arjan
2002-02-01 19:47 ` Jeff Garzik
2002-02-02 15:39 ` Rik van Riel
2002-02-05 14:21 ` Pavel Machek
2002-02-05 18:45 ` Rik van Riel
2002-02-05 20:30 ` Eric Dumazet
2002-02-05 20:46 ` Pavel Machek
2002-02-06 9:07 ` Daniel Phillips
2002-02-05 9:19 ` Zdenek Kabelac
2002-02-01 23:49 ` Ingo Molnar
2002-02-01 14:44 ` Andrea Arcangeli
2002-02-01 14:59 ` Momchil Velikov
2002-02-01 17:03 ` Ingo Molnar
2002-02-01 15:26 ` Momchil Velikov
2002-02-01 23:45 ` Ingo Molnar
2002-01-31 10:41 ` Josh MacDonald
2002-01-31 14:00 ` Rik van Riel
2002-01-31 14:21 ` Momchil Velikov
2002-01-30 22:22 ` Christoph Hellwig
2002-01-30 3:02 ` Daniel Phillips
2002-01-29 23:00 ` William Lee Irwin III
-- strict thread matches above, loose matches on Subject: below --
2002-02-02 19:23 rwhron
2002-02-03 14:31 ` chris
2002-02-03 23:33 ` Momchil Velikov
2002-02-04 3:59 ` rwhron
2002-02-06 2:04 ` rwhron
2002-02-06 11:44 ` Rik van Riel
2002-02-06 21:34 rwhron
2002-02-06 21:37 ` Rik van Riel
2002-02-06 22:06 ` rwhron
2002-02-07 11:32 ` Daniel Phillips
2002-02-07 11:32 ` Daniel Phillips
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