Still seeing hangs in xlog_grant_log_space

[Juerg Haefliger]

> Does your kernel have the effect of
>
> 0bf6a5bd4b55b466964ead6fa566d8f346a828ee xfs: convert the xfsaild
> thread to a workqueue

No.


> c7eead1e118fb7e34ee8f5063c3c090c054c3820 xfs: revert to using a
> kthread for AIL pushing

No.


> In particular, is this code in xfs_trans_ail_push:
>
>       smp_wmb();
>       xfs_trans_ail_copy_lsn(ailp, &ailp->xa_target, &threshold_lsn);
>       smp_wmb();

No. xfs_trans_ail_push looks like this:

void
xfs_trans_ail_push(
        struct xfs_ail  *ailp,
        xfs_lsn_t       threshold_lsn)
{
        xfs_log_item_t  *lip;

        lip = xfs_ail_min(ailp);
        if (lip && !XFS_FORCED_SHUTDOWN(ailp->xa_mount)) {
                if (XFS_LSN_CMP(threshold_lsn, ailp->xa_target) > 0)
                        xfsaild_wakeup(ailp, threshold_lsn);
        }
}


FWIW, the XFS driver in my kernel is identical to the vanilla 2.6.38
driver. I'm still trying to get a XFS trace from a production hang. I
do have a crash dump from a production machine with /tmp hanging.
Would it be helpful to share that dump?

...Juerg