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; if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) { bp->b_flags |= XBF_FUA; @@ -1854,6 +1856,8 @@ xlog_sync( bp->b_flags |= XBF_SYNCIO; if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) bp->b_flags |= XBF_FUA; + /* use high priority completion wq */ + bp->b_ioend_wq = log->l_mp->m_log_workqueue; ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1); ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize); diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index fee11c8..7a833c3 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -839,8 +839,7 @@ xfs_init_mount_workqueues( struct xfs_mount *mp) { mp->m_buf_workqueue = alloc_workqueue("xfs-buf/%s", - WQ_MEM_RECLAIM|WQ_HIGHPRI|WQ_FREEZABLE, 1, - mp->m_fsname); + WQ_MEM_RECLAIM|WQ_FREEZABLE, 1, mp->m_fsname); if (!mp->m_buf_workqueue) goto out; @@ -865,7 +864,7 @@ xfs_init_mount_workqueues( goto out_destroy_cil; mp->m_log_workqueue = alloc_workqueue("xfs-log/%s", - WQ_FREEZABLE, 0, mp->m_fsname); + WQ_FREEZABLE|WQ_HIGHPRI, 0, mp->m_fsname); if (!mp->m_log_workqueue) goto out_destroy_reclaim; -- 1.8.3.1 _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
