Date: Wed, 30 Jun 2010 22:07:31 +1000
From: Nick Piggin <npiggin@suse.de>
To: Dave Chinner <david@fromorbit.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
       John Stultz <johnstul@us.ibm.com>, Frank Mayhar <fmayhar@google.com>
Subject: Re: [patch 38/52] fs: icache RCU free inodes
Message-ID: <20100630120731.GD21358@laptop>
References: <20100624030212.676457061@suse.de>
 <20100624030731.710413510@suse.de>
 <20100630085711.GH24712@dastard>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20100630085711.GH24712@dastard>
User-Agent: Mutt/1.5.20 (2009-06-14)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1216
Lines: 26

On Wed, Jun 30, 2010 at 06:57:11PM +1000, Dave Chinner wrote:
> On Thu, Jun 24, 2010 at 01:02:50PM +1000, npiggin@suse.de wrote:
> > RCU free the struct inode. This will allow:
> 
> Rather than what it will allow, what are the constraints this
> imposes on allocating and freeing a struct inode?  e.g. XFS embeds
> the struct inode in a larger inode structure and does it's own
> allocation, caching and freeing of the larger structure outside of
> the VFS functionality.
> 
> Does this need to be converted to RCU? Do we need to do more
> initialisation of the struct inode than we currently do? What
> functions/call chains now implicitly require RCU freeing semantics
> on the struct inode for safe operation? What else do we need to be
> aware of?

Yeah, filesystems with their own freeing functions will need to
do a call_rcu to free it (many are not converted). Otherwise,
there is nothing else to know. They could take advantage of RCU
if they would like though.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/