From f85d9f2d02cdcd1b79e00fccd667b37b251ba3ac Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Mon, 18 May 2015 14:08:46 +0200 Subject: [PATCH] drbd: fix "endless" transfer log walk in protocol A Don't remember a DRBD request as ack_pending, if it is not. In protocol A, we usually clear RQ_NET_PENDING at the same time we set RQ_NET_SENT, so when deciding to remember it as ack_pending, mod_rq_state needs to look at the current request state, not at the previous state before the current modification was applied. This should prevent advance_conn_req_ack_pending() from walking the full transfer log just to find NULL in protocol A, which would cause serious performance degradation with many "in-flight" requests, e.g. when working via DRBD-proxy, or with a huge bandwidth-delay product. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_req.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 7907fb562388..2255dcfebd2b 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -458,7 +458,7 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, atomic_add(req->i.size >> 9, &device->ap_in_flight); set_if_null_req_not_net_done(peer_device, req); } - if (s & RQ_NET_PENDING) + if (req->rq_state & RQ_NET_PENDING) set_if_null_req_ack_pending(peer_device, req); } -- 2.20.1