Re: [PATCH 4/8] XFS: Allow 64 bit machines to avoid the AIL lock during flushes

Christoph Hellwig
2008-09-19T09:24:56Z

On Sun, Sep 14, 2008 at 12:57:53AM +1000, Dave Chinner wrote:
> When copying lsn's from the log item to the inode or dquot
> flush lsn, we currently grab the AIL lock. We do this because the
> LSN is a 64 bit quantity and it needs to be read atomically.
> The lock is used to guarantee atomicity for 32 bit platforms.
>
> Make the LSN copying a small function, and make the function
> used conditional on BITS_PER_LONG so that 64 bit machines don't
> need to take the AIL lock in these places.

Looks good.