On Thu, Feb 27, 2014 at 11:44:22AM -0800, Alex Wang wrote: > This commit changes the API in 'dpif-provider.h' to allow multiple > handler threads call dpif_recv() simultaneously. > > Signed-off-by: Alex Wang <al...@nicira.com>
The comment on dpif_port_get_pid() says that the 'hash' parameter should be a 5-tuple hash. Does it have be calculated a specific way? This appears to delete the comment on dpif_recv_set(), instead of updating it. In particular I don't know exactly what 'n_handlers' means. It isn't clear to me where the 'handler_id's come from. I noticed that new comments talk about "multiple clients", meaning multiple threads reading packets from a single "struct dpif *". Old comments also talked about multiple clients, but they meant different "struct dpif *"s (often from different processes) referring to a single datapath. I'm appending an incremental that tries to clarify that. My incremental also makes the suggestions for handling multiple threads more specific; I'm not sure that my more specific suggestions are actually what you mean, so please clarify if I misunderstood. diff --git a/lib/dpif.h b/lib/dpif.h index 8079751..2d3a50f 100644 --- a/lib/dpif.h +++ b/lib/dpif.h @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc. + * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -205,10 +205,10 @@ * connection consists of two flows with 1-ms latency to set up each one. * * To receive upcalls, a client has to enable them with dpif_recv_set(). A - * datapath should generally support multiple clients at once (e.g. so that one - * may run "ovs-dpctl show" or "ovs-dpctl dump-flows" while "ovs-vswitchd" is - * also running) but need not support multiple clients enabling upcalls at - * once. + * datapath should generally support being opened multiple times (e.g. so that + * one may run "ovs-dpctl show" or "ovs-dpctl dump-flows" while "ovs-vswitchd" + * is also running) but need not support more than one of these clients + * enabling upcalls at once. * * * Upcall Queuing and Ordering @@ -261,7 +261,7 @@ * PID in "action" upcalls is that dpif_port_get_pid() returns a constant value * and all upcalls are appended to a single queue. * - * The ideal behavior is: + * The preferred behavior is: * * - Each port has a PID that identifies the queue used for "miss" upcalls * on that port. (Thus, if each port has its own queue for "miss" @@ -275,16 +275,13 @@ * * - Upcalls that specify the "special" Netlink PID are queued separately. * + * Multiple threads may want to read upcalls simultaneously from a single + * datapath. To support multiple threads well, one extends the above preferred + * behavior: * - * Multiple Clients - * ---------------- - * A datapath may have more than one client and multiple clients may want - * to read upcalls simultaneously. In such situation, the additional - * requirements on the datapath are: - * - * - The datapath must provide a set of per-port Netlink PIDs to each - * client. The distribution of "miss" upcalls must guarantee that the - * same flow should always go to the same socket's receive queue. + * - Each port has multiple PIDs. The datapath distributes "miss" upcalls + * across the PIDs, ensuring that a given flow is mapped in a stable way + * to a single PID. * * - For "action" upcalls, the client can specify its own Netlink PID or * other client's Netlink PID of the same port for offloading purpose _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
