Re: drop_pagecache: Possible circular locking dependency

From: Andrew Morton
Date: Mon Dec 04 2006 - 03:33:00 EST


On Mon, 4 Dec 2006 16:09:02 +0800
Fengguang Wu <fengguang.wu@xxxxxxxxx> wrote:

> Got the following message when doing some benchmarks.
> I guess we should not hold inode_lock on calling invalidate_inode_pages().
> Any ideas?
>
> Fengguang Wu
>
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.19-rc6-mm2 #3
> -------------------------------------------------------
> rabench.sh/7467 is trying to acquire lock:
> (&journal->j_list_lock){--..}, at: [<ffffffff8113bdbc>] journal_try_to_free_buffers+0xdc/0x1c0
>
> but task is already holding lock:
> (inode_lock){--..}, at: [<ffffffff810fe857>] drop_pagecache+0x67/0x120
>
> which lock already depends on the new lock.
>

drat, I was afraid someone would notice.

It's Hard To Fix. Removing /proc/sys/vm/drop_pagecache would in fact be
my preferred fix.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/