Re: INFO: possible circular locking dependency detected

From: Nick Piggin
Date: Mon Oct 16 2006 - 11:46:59 EST


Randy Dunlap wrote:
On Tue, 17 Oct 2006 00:32:44 +1000 Nick Piggin wrote:


alpha @ steudten Engineering wrote:

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.18-1.2189self #1
-------------------------------------------------------
kswapd0/186 is trying to acquire lock:
(&inode->i_mutex){--..}, at: [<c0326e32>] mutex_lock+0x21/0x24

but task is already holding lock:
(iprune_mutex){--..}, at: [<c0326e32>] mutex_lock+0x21/0x24

which lock already depends on the new lock.

Thanks. __grab_cache_page wants to clear __GFP_FS, because it is
holding the i_mutex so we don't want to reenter the filesystem in
page reclaim.

This would be an easy two liner, except those funny page_cache_alloc
routines which take a mapping rather than a gfp_t argument :P


and it would be only one email, but you forgot spaces there,
so it's too ugly to use. ;) i.e., please add spaces around
the '&'.

and it's an attachment :(

Oh yeah, it was an attachment because I didn't want anyone to see how
ugly it is ;)

It's just a quick hack to see if it works. I'll send out a real patch
when I get time to code and test it properly.

--
SUSE Labs, Novell Inc.
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