On Wed, Dec 03, 2014 at 02:24:19PM -0500, Brian Foster wrote: > XFS traditionally sends all buffer I/O completion work to a single > workqueue. This includes metadata buffer completion and log buffer > completion. The log buffer completion requires a high priority queue to > prevent stalls due to log forces getting stuck behind other queued work. > > Rather than continue to prioritize all buffer I/O completion due to the > needs of log completion, split log buffer completion off to > m_log_workqueue and move the high priority flag from m_buf_workqueue to > m_log_workqueue. > > Add a b_ioend_wq wq pointer to xfs_buf to allow completion workqueue > customization on a per-buffer basis. Initialize b_ioend_wq to > m_buf_workqueue by default in the generic buffer I/O submission path. > Finally, override the default wq with the high priority m_log_workqueue > in the log buffer I/O submission path. > > Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx> > --- > > v2: > - Add bp->b_ioend_wq pointer to multiplex buffer I/O completion > workqueues. > v1/rfc: http://oss.sgi.com/archives/xfs/2014-11/msg00240.html > > fs/xfs/xfs_buf.c | 13 ++++++++++--- > fs/xfs/xfs_buf.h | 3 ++- > fs/xfs/xfs_log.c | 4 ++++ > fs/xfs/xfs_super.c | 5 ++--- > 4 files changed, 18 insertions(+), 7 deletions(-) > > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index a4ce390..bb502a3 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -1041,7 +1041,7 @@ xfs_buf_ioend_work( > struct work_struct *work) > { > struct xfs_buf *bp = > - container_of(work, xfs_buf_t, b_iodone_work); > + container_of(work, xfs_buf_t, b_ioend_work); > > xfs_buf_ioend(bp); > } > @@ -1050,8 +1050,8 @@ void > xfs_buf_ioend_async( > struct xfs_buf *bp) > { > - INIT_WORK(&bp->b_iodone_work, xfs_buf_ioend_work); > - queue_work(bp->b_target->bt_mount->m_buf_workqueue, &bp->b_iodone_work); > + INIT_WORK(&bp->b_ioend_work, xfs_buf_ioend_work); > + queue_work(bp->b_ioend_wq, &bp->b_ioend_work); > } > > void > @@ -1220,6 +1220,13 @@ _xfs_buf_ioapply( > */ > bp->b_error = 0; > > + /* > + * Initialize the I/O completion workqueue if we haven't yet or the > + * submitter has not opted to specify a custom one. > + */ > + if (!bp->b_ioend_wq) > + bp->b_ioend_wq = bp->b_target->bt_mount->m_buf_workqueue; > + > if (bp->b_flags & XBF_WRITE) { > if (bp->b_flags & XBF_SYNCIO) > rw = WRITE_SYNC; > diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h > index 82002c0..75ff5d5 100644 > --- a/fs/xfs/xfs_buf.h > +++ b/fs/xfs/xfs_buf.h > @@ -164,7 +164,8 @@ typedef struct xfs_buf { > struct xfs_perag *b_pag; /* contains rbtree root */ > xfs_buftarg_t *b_target; /* buffer target (device) */ > void *b_addr; /* virtual address of buffer */ > - struct work_struct b_iodone_work; > + struct work_struct b_ioend_work; > + struct workqueue_struct *b_ioend_wq; /* I/O completion wq */ > xfs_buf_iodone_t b_iodone; /* I/O completion function */ > struct completion b_iowait; /* queue for I/O waiters */ > void *b_fspriv; > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index f6d6b8b..e408bf5 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -1806,6 +1806,8 @@ xlog_sync( > XFS_BUF_ZEROFLAGS(bp); > XFS_BUF_ASYNC(bp); > bp->b_flags |= XBF_SYNCIO; > + /* use high priority completion wq */ > + bp->b_ioend_wq = log->l_mp->m_log_workqueue; We reuse the log buffers so this should only need to be set at initialisation time whent eh buffers are allocated. Minor issue, though - send a followup patch that just moves this. Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
