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Date: Sun, 26 Oct 2003 14:19:44 -0600
From: Alan Cox <alc@cs.rice.edu>
To: Alan Cox <alc@FreeBSD.org>
Message-ID: <20031026201944.GA20658@cs.rice.edu>
References: <200310261955.h9QJtZrn085565@repoman.freebsd.org>
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Subject: Re: cvs commit: src/sys/vm swap_pager.c
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With this change, you may see:

lock order reversal
 1st 0xc24aab90 vm object (vm object) @ vm/swap_pager.c:1319
 2nd 0xc070f180 swap_pager swhash (swap_pager swhash) @ vm/swap_pager.c:1832
 3rd 0xc1036b90 vm object (vm object) @ vm/uma_core.c:876

This is also a false positive.  The only vm object that is locked
after acquiring the "swap_pager swhash" mutex is one used internally
in UMA.  We will never acquire this vm object's mutex followed by
the "swap_pager swhash" mutex.

Regards,
Alan

On Sun, Oct 26, 2003 at 11:55:35AM -0800, Alan Cox wrote:
> alc         2003/10/26 11:55:35 PST
> 
>   FreeBSD src repository
> 
>   Modified files:
>     sys/vm               swap_pager.c 
>   Log:
>    - Introduce and use a mutex synchronizing access to the swblock hash table.
>   
>   Revision  Changes    Path
>   1.234     +20 -4     src/sys/vm/swap_pager.c