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From: Paolo Bonzini <pbonzini@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org,
	"Michael R. Hines" <mrhines@linux.vnet.ibm.com>,
	owasserm@redhat.com, abali@us.ibm.com, mrhines@us.ibm.com,
	gokul@us.ibm.com
Subject: Re: [Qemu-devel] [RFC PATCH RDMA support v5: 03/12] comprehensive protocol documentation
Date: Thu, 11 Apr 2013 16:50:21 +0200	[thread overview]
Message-ID: <5166CDAD.8060807@redhat.com> (raw)
In-Reply-To: <20130411143718.GC24942@redhat.com>

Il 11/04/2013 16:37, Michael S. Tsirkin ha scritto:
> 
> pg1 ->  pin -> req -> res -> rdma -> done
>         pg2 ->  pin -> req -> res -> rdma -> done
>                 pg3 -> pin -> req -> res -> rdma -> done
>                        pg4 -> pin -> req -> res -> rdma -> done
>                               pg4 -> pin -> req -> res -> rdma -> done
> 
> It's like a assembly line see?  So while software does the registration
> roundtrip dance, hardware is processing rdma requests for previous
> chunks.

Does this only affects the implementation, or also the wire protocol?
Does the destination have to be aware that the source is doing pipelining?

Paolo

> 
> ....
> 
> When do you have to stall? when you run out of rx buffer credits so you
> can not start a new req.  Your protocol has 2 outstanding buffers,
> so you can only have one req in the air. Do more and
> you will not need to stall - possibly at all.
> 
> One other minor point is that your protocol requires extra explicit
> ready commands. You can pass the number of rx buffers as extra payload
> in the traffic you are sending anyway, and reduce that overhead.

  reply	other threads:[~2013-04-11 14:51 UTC|newest]

Thread overview: 97+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-09  3:04 [Qemu-devel] [RFC PATCH RDMA support v5: 00/12] new formal protocol design mrhines
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 01/12] ./configure with and without --enable-rdma mrhines
2013-04-09 17:05   ` Paolo Bonzini
2013-04-09 18:07     ` Michael R. Hines
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 02/12] check for CONFIG_RDMA mrhines
2013-04-09 16:46   ` Paolo Bonzini
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 03/12] comprehensive protocol documentation mrhines
2013-04-10  5:27   ` Michael S. Tsirkin
2013-04-10 13:04     ` Michael R. Hines
2013-04-10 13:34       ` Michael S. Tsirkin
2013-04-10 15:29         ` Michael R. Hines
2013-04-10 17:41           ` Michael S. Tsirkin
2013-04-10 20:05             ` Michael R. Hines
2013-04-11  7:19               ` Michael S. Tsirkin
2013-04-11 13:12                 ` Michael R. Hines
2013-04-11 13:48                   ` Michael S. Tsirkin
2013-04-11 13:58                     ` Michael R. Hines
2013-04-11 14:37                       ` Michael S. Tsirkin
2013-04-11 14:50                         ` Paolo Bonzini [this message]
2013-04-11 14:56                           ` Michael S. Tsirkin
2013-04-11 17:49                             ` Michael R. Hines
2013-04-11 19:15                               ` Michael S. Tsirkin
2013-04-11 20:33                                 ` Michael R. Hines
2013-04-12 10:48                                   ` Michael S. Tsirkin
2013-04-12 10:53                                     ` Paolo Bonzini
2013-04-12 11:25                                       ` Michael S. Tsirkin
2013-04-12 14:43                                         ` Paolo Bonzini
2013-04-14 11:59                                           ` Michael S. Tsirkin
2013-04-14 14:09                                             ` Paolo Bonzini
2013-04-14 14:40                                               ` Michael R. Hines
2013-04-14 14:27                                             ` Michael R. Hines
2013-04-14 16:03                                               ` Michael S. Tsirkin
2013-04-14 16:07                                                 ` Michael R. Hines
2013-04-14 16:40                                                 ` Michael R. Hines
2013-04-14 18:30                                                   ` Michael S. Tsirkin
2013-04-14 19:06                                                     ` Michael R. Hines
2013-04-14 21:10                                                       ` Michael S. Tsirkin
2013-04-15  1:06                                                         ` Michael R. Hines
2013-04-15  6:00                                                           ` Michael S. Tsirkin
2013-04-15 13:07                                                             ` Michael R. Hines
2013-04-15 22:20                                                               ` Michael S. Tsirkin
2013-04-15  8:28                                                           ` Paolo Bonzini
2013-04-15 13:08                                                             ` Michael R. Hines
2013-04-15  8:26                                                       ` Paolo Bonzini
2013-04-12 13:47                                     ` Michael R. Hines
2013-04-14  8:28                                       ` Michael S. Tsirkin
2013-04-14 14:31                                         ` Michael R. Hines
2013-04-14 18:51                                           ` Michael S. Tsirkin
2013-04-14 19:43                                             ` Michael R. Hines
2013-04-14 21:16                                               ` Michael S. Tsirkin
2013-04-15  1:10                                                 ` Michael R. Hines
2013-04-15  6:10                                                   ` Michael S. Tsirkin
2013-04-15  8:34                                                   ` Paolo Bonzini
2013-04-15 13:24                                                     ` Michael R. Hines
2013-04-15 13:30                                                       ` Paolo Bonzini
2013-04-15 19:55                                                         ` Michael R. Hines
2013-04-11 15:01                           ` Michael R. Hines
2013-04-11 15:18                         ` Michael R. Hines
2013-04-11 15:33                           ` Paolo Bonzini
2013-04-11 15:46                             ` Michael S. Tsirkin
2013-04-11 15:47                               ` Paolo Bonzini
2013-04-11 15:58                                 ` Michael S. Tsirkin
2013-04-11 16:06                                   ` Michael R. Hines
2013-04-12  5:10                             ` Michael R. Hines
2013-04-12  5:26                               ` Paolo Bonzini
2013-04-12  5:54                                 ` Michael R. Hines
2013-04-11 15:44                           ` Michael S. Tsirkin
2013-04-11 16:09                             ` Michael R. Hines
2013-04-11 17:04                               ` Michael S. Tsirkin
2013-04-11 17:27                                 ` Michael R. Hines
2013-04-11 16:13                             ` Michael R. Hines
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 04/12] introduce qemu_ram_foreach_block() mrhines
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 05/12] core RDMA migration logic w/ new protocol mrhines
2013-04-09 16:57   ` Paolo Bonzini
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 06/12] connection-establishment for RDMA mrhines
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 07/12] additional savevm.c accessors " mrhines
2013-04-09 17:03   ` Paolo Bonzini
2013-04-09 17:31   ` Peter Maydell
2013-04-09 18:04     ` Michael R. Hines
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 08/12] new capabilities added and check for QMP string 'rdma' mrhines
2013-04-09 17:01   ` Paolo Bonzini
2013-04-10  1:11     ` Michael R. Hines
2013-04-10  8:07       ` Paolo Bonzini
2013-04-10 10:35         ` Michael S. Tsirkin
2013-04-10 12:24         ` Michael R. Hines
2013-04-09 17:02   ` Paolo Bonzini
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 09/12] transmit pc.ram using RDMA mrhines
2013-04-09 16:50   ` Paolo Bonzini
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 10/12] new header file prototypes for savevm.c mrhines
2013-04-09 16:43   ` Paolo Bonzini
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 11/12] update schema to define new capabilities mrhines
2013-04-09 16:43   ` Paolo Bonzini
2013-04-09  3:04 ` [Qemu-devel] [RFC PATCH RDMA support v5: 12/12] don't set nonblock on invalid file descriptor mrhines
2013-04-09 16:45   ` Paolo Bonzini
2013-04-09  4:24 ` [Qemu-devel] [RFC PATCH RDMA support v5: 00/12] new formal protocol design Michael R. Hines
2013-04-09 12:44 ` Michael S. Tsirkin
2013-04-09 14:23   ` Michael R. Hines

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