From 2c7da8e6b041a8df2661def81ac90c9c0c719909 Mon Sep 17 00:00:00 2001 From: Gerd Rausch Date: Tue, 16 Jul 2019 15:28:51 -0700 Subject: net/rds: Give fr_state a chance to transition to FRMR_IS_FREE In the context of FRMR (ib_frmr.c): 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 "rds_ib_mr_cqe_handler", which is triggered by a tasklet. So in case we notice that "fr_state != FRMR_IS_FREE" (see below), we wait for "fr_inv_done" to trigger with a maximum of 10msec. Then we check again, and only put the memory region onto the drop_list (via "rds_ib_free_frmr") in case the situation remains unchanged. This avoids the problem of memory-regions bouncing between "clean_list" and "drop_list" before they even have a chance to be properly invalidated. Signed-off-by: Gerd Rausch Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller --- net/rds/ib_mr.h | 1 + 1 file changed, 1 insertion(+) (limited to 'net/rds/ib_mr.h') diff --git a/net/rds/ib_mr.h b/net/rds/ib_mr.h index 5da12c248431..42daccb7b5eb 100644 --- a/net/rds/ib_mr.h +++ b/net/rds/ib_mr.h @@ -57,6 +57,7 @@ struct rds_ib_frmr { struct ib_mr *mr; enum rds_ib_fr_state fr_state; bool fr_inv; + wait_queue_head_t fr_inv_done; struct ib_send_wr fr_wr; unsigned int dma_npages; unsigned int sg_byte_len; -- cgit v1.2.3