diff options
Diffstat (limited to 'net/rds/ib_frmr.c')
| -rw-r--r-- | net/rds/ib_frmr.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c index 32ae26ed58a0..6038138d6e38 100644 --- a/net/rds/ib_frmr.c +++ b/net/rds/ib_frmr.c @@ -75,6 +75,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, pool->max_items_soft = pool->max_items; frmr->fr_state = FRMR_IS_FREE; + init_waitqueue_head(&frmr->fr_inv_done); return ibmr; out_no_cigar: @@ -285,6 +286,7 @@ void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc) if (frmr->fr_inv) { frmr->fr_state = FRMR_IS_FREE; frmr->fr_inv = false; + wake_up(&frmr->fr_inv_done); } atomic_inc(&ic->i_fastreg_wrs); @@ -345,8 +347,31 @@ struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev, } do { - if (ibmr) + if (ibmr) { + /* Memory regions make it onto the "clean_list" via + * "rds_ib_flush_mr_pool", after the memory region has + * been posted for invalidation via "rds_ib_post_inv". + * + * At that point in time, "fr_state" may still be + * in state "FRMR_IS_INUSE", since the only place where + * "fr_state" transitions to "FRMR_IS_FREE" is in + * is in "rds_ib_mr_cqe_handler", which is + * triggered by a tasklet. + * + * So we wait for "fr_inv_done" to trigger + * and only put memory regions onto the drop_list + * that failed (i.e. not marked "FRMR_IS_FREE"). + * + * This avoids the problem of memory-regions bouncing + * between "clean_list" and "drop_list" before they + * even have a chance to be properly invalidated. + */ + frmr = &ibmr->u.frmr; + wait_event(frmr->fr_inv_done, frmr->fr_state != FRMR_IS_INUSE); + if (frmr->fr_state == FRMR_IS_FREE) + break; rds_ib_free_frmr(ibmr, true); + } ibmr = rds_ib_alloc_frmr(rds_ibdev, nents); if (IS_ERR(ibmr)) return ibmr; |