• Christoph Hellwig's avatar
    xfs: revert to using a kthread for AIL pushing · 0030807c
    Christoph Hellwig authored
    Currently we have a few issues with the way the workqueue code is used to
    implement AIL pushing:
    
     - it accidentally uses the same workqueue as the syncer action, and thus
       can be prevented from running if there are enough sync actions active
       in the system.
     - it doesn't use the HIGHPRI flag to queue at the head of the queue of
       work items
    
    At this point I'm not confident enough in getting all the workqueue flags and
    tweaks right to provide a perfectly reliable execution context for AIL
    pushing, which is the most important piece in XFS to make forward progress
    when the log fills.
    
    Revert back to use a kthread per filesystem which fixes all the above issues
    at the cost of having a task struct and stack around for each mounted
    filesystem.  In addition this also gives us much better ways to diagnose
    any issues involving hung AIL pushing and removes a small amount of code.
    Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
    Reported-by: default avatarStefan Priebe <s.priebe@profihost.ag>
    Tested-by: default avatarStefan Priebe <s.priebe@profihost.ag>
    Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
    Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
    0030807c
xfs_linux.h 7.5 KB