diff mbox series

[for-next,v2] RDMA/cma: Fix incorrect Packet Lifetime calculation

Message ID 1624371207-26710-1-git-send-email-haakon.bugge@oracle.com (mailing list archive)
State Accepted
Delegated to: Jason Gunthorpe
Headers show
Series [for-next,v2] RDMA/cma: Fix incorrect Packet Lifetime calculation | expand

Commit Message

Haakon Bugge June 22, 2021, 2:13 p.m. UTC
An approximation for the PacketLifeTime is half the local ACK timeout.
The encoding for both timers are logarithmic.

If the local ACK timeout is set, but zero, it means the timer is
disabled. In this case, we choose the CMA_IBOE_PACKET_LIFETIME value,
since 50% of infinite makes no sense.

Before this commit, the PacketLifeTime became 255 if local ACK
timeout was zero (not running).

Fixed by explicitly testing for timeout being zero.

Fixes: e1ee1e62bec4 ("RDMA/cma: Use ACK timeout for RoCE packetLifeTime")
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

---

	v1 -> v2:
	   * Rebased on tip of for-next with ("RDMA/cma: Protect RMW
	     with qp_mutex") included
	   * A local ACK timeout of zero now sets PacketLifeTime to
             CMA_IBOE_PACKET_LIFETIME
	   * Added Leon's r-b
---
 drivers/infiniband/core/cma.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Jason Gunthorpe June 25, 2021, 2:44 p.m. UTC | #1
On Tue, Jun 22, 2021 at 04:13:27PM +0200, Håkon Bugge wrote:
> An approximation for the PacketLifeTime is half the local ACK timeout.
> The encoding for both timers are logarithmic.
> 
> If the local ACK timeout is set, but zero, it means the timer is
> disabled. In this case, we choose the CMA_IBOE_PACKET_LIFETIME value,
> since 50% of infinite makes no sense.
> 
> Before this commit, the PacketLifeTime became 255 if local ACK
> timeout was zero (not running).
> 
> Fixed by explicitly testing for timeout being zero.
> 
> Fixes: e1ee1e62bec4 ("RDMA/cma: Use ACK timeout for RoCE packetLifeTime")
> Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
> Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
> ---
> 
> 	v1 -> v2:
> 	   * Rebased on tip of for-next with ("RDMA/cma: Protect RMW
> 	     with qp_mutex") included
> 	   * A local ACK timeout of zero now sets PacketLifeTime to
>              CMA_IBOE_PACKET_LIFETIME
> 	   * Added Leon's r-b
> ---
>  drivers/infiniband/core/cma.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

Applied to for-next, thanks

Jason
diff mbox series

Patch

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index c44a0c4..35fe300 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3080,8 +3080,10 @@  static int cma_resolve_iboe_route(struct rdma_id_private *id_priv)
 	 * as a reasonable approximation for RoCE networks.
 	 */
 	mutex_lock(&id_priv->qp_mutex);
-	route->path_rec->packet_life_time = id_priv->timeout_set ?
-		id_priv->timeout - 1 : CMA_IBOE_PACKET_LIFETIME;
+	if (id_priv->timeout_set && id_priv->timeout)
+		route->path_rec->packet_life_time = id_priv->timeout - 1;
+	else
+		route->path_rec->packet_life_time = CMA_IBOE_PACKET_LIFETIME;
 	mutex_unlock(&id_priv->qp_mutex);
 
 	if (!route->path_rec->mtu) {