From: Randy Dunlap <randy.dunlap@oracle•com>
To: Krishna Kumar <krkumar2@in•ibm.com>
Cc: johnpol@2ka•mipt.ru, jagana@us•ibm.com,
herbert@gondor•apana.org.au, gaagaan@gmail•com,
Robert.Olsson@data•slu.se, kumarkr@linux•ibm.com,
rdreier@cisco•com, peter.p.waskiewicz.jr@intel•com,
hadi@cyberus•ca, kaber@trash•net, jeff@garzik•org,
general@lists•openfabrics.org, netdev@vger•kernel.org,
tgraf@suug•ch, mcarlson@broadcom•com, sri@us•ibm.com,
shemminger@linux-foundation•org, davem@davemloft•net,
mchan@broadcom•com
Subject: [ofa-general] Re: [PATCH 1/10 REV5] [Doc] HOWTO Documentation for batching
Date: Fri, 14 Sep 2007 11:37:09 -0700 [thread overview]
Message-ID: <20070914113709.80baba4d.randy.dunlap@oracle.com> (raw)
In-Reply-To: <20070914090118.17589.43799.sendpatchset@K50wks273871wss.in.ibm.com>
On Fri, 14 Sep 2007 14:31:18 +0530 Krishna Kumar wrote:
> Add Documentation describing batching skb xmit capability.
>
> Signed-off-by: Krishna Kumar <krkumar2@in•ibm.com>
> ---
> batching_skb_xmit.txt | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 107 insertions(+)
>
> diff -ruNp org/Documentation/networking/batching_skb_xmit.txt new/Documentation/networking/batching_skb_xmit.txt
> --- org/Documentation/networking/batching_skb_xmit.txt 1970-01-01 05:30:00.000000000 +0530
> +++ new/Documentation/networking/batching_skb_xmit.txt 2007-09-14 10:25:36.000000000 +0530
> @@ -0,0 +1,107 @@
> +
> +Section 4: Nitty gritty details for driver writers
> +--------------------------------------------------
> +
> + Batching is enabled from core networking stack only from softirq
> + context (NET_TX_SOFTIRQ), and dev_queue_xmit() doesn't use batching.
> +
> + This leads to the following situation:
> + A skb was not sent out as either driver lock was contested or
> + the device was blocked. When the softirq handler runs, it
> + moves all skbs from the device queue to the batch list, but
> + then it too could fail to send due to lock contention. The
> + next xmit (of a single skb) called from dev_queue_xmit() will
> + not use batching and try to xmit skb, while previous skbs are
> + still present in the batch list. This results in the receiver
> + getting out-of-order packets, and in case of TCP the sender
> + would have unnecessary retransmissions.
> +
> + To fix this problem, error cases where driver xmit gets called with a
> + skb must code as follows:
> + 1. If driver xmit cannot get tx lock, return NETDEV_TX_LOCKED
> + as usual. This allows qdisc to requeue the skb.
> + 2. If driver xmit got the lock but failed to send the skb, it
> + should return NETDEV_TX_BUSY but before that it should have
> + queue'd the skb to the batch list. In this case, the qdisc
queued
> + does not requeue the skb.
and then
Acked-by: Randy Dunlap <randy.dunlap@oracle•com>
Thanks,
---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***
next prev parent reply other threads:[~2007-09-14 18:37 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-14 9:00 [PATCH 0/10 REV5] Implement skb batching and support in IPoIB/E1000 Krishna Kumar
2007-09-14 9:01 ` [PATCH 1/10 REV5] [Doc] HOWTO Documentation for batching Krishna Kumar
2007-09-14 18:37 ` Randy Dunlap [this message]
2007-09-17 4:10 ` Krishna Kumar2
2007-09-17 4:13 ` [ofa-general] " Jeff Garzik
2007-09-14 9:01 ` [PATCH 2/10 REV5] [core] Add skb_blist & support " Krishna Kumar
2007-09-14 12:46 ` [ofa-general] " Evgeniy Polyakov
2007-09-17 3:51 ` Krishna Kumar2
2007-09-14 9:01 ` [PATCH 3/10 REV5] [sched] Modify qdisc_run to support batching Krishna Kumar
2007-09-14 12:15 ` [ofa-general] " Evgeniy Polyakov
2007-09-17 3:49 ` Krishna Kumar2
2007-09-14 9:02 ` [PATCH 4/10 REV5] [ethtool] Add ethtool support Krishna Kumar
2007-09-14 9:02 ` [PATCH 5/10 REV5] [IPoIB] Header file changes Krishna Kumar
2007-09-14 9:03 ` [PATCH 6/10 REV5] [IPoIB] CM & Multicast changes Krishna Kumar
2007-09-14 9:03 ` [PATCH 7/10 REV5] [IPoIB] Verbs changes Krishna Kumar
2007-09-14 9:03 ` [PATCH 8/10 REV5] [IPoIB] Post and work completion handler changes Krishna Kumar
2007-09-14 9:04 ` [PATCH 9/10 REV5] [IPoIB] Implement batching Krishna Kumar
2007-09-14 9:04 ` [PATCH 10/10 REV5] [E1000] " Krishna Kumar
2007-09-14 12:47 ` [ofa-general] " Evgeniy Polyakov
2007-09-17 3:56 ` Krishna Kumar2
2007-11-13 21:28 ` [ofa-general] " Kok, Auke
2007-11-14 8:30 ` Krishna Kumar2
2007-09-14 12:49 ` [ofa-general] Re: [PATCH 0/10 REV5] Implement skb batching and support in IPoIB/E1000 Evgeniy Polyakov
2007-09-16 23:17 ` David Miller
2007-09-17 0:29 ` jamal
2007-09-17 1:02 ` David Miller
2007-09-17 2:14 ` [ofa-general] " jamal
2007-09-17 2:25 ` David Miller
2007-09-17 3:01 ` jamal
2007-09-17 3:13 ` David Miller
2007-09-17 12:51 ` jamal
2007-09-17 16:37 ` [ofa-general] " David Miller
2007-09-17 4:46 ` Krishna Kumar2
2007-09-23 17:53 ` [PATCHES] TX batching jamal
2007-09-23 17:56 ` [ofa-general] [PATCH 1/4] [NET_SCHED] explict hold dev tx lock jamal
2007-09-23 17:58 ` [ofa-general] [PATCH 2/4] [NET_BATCH] Introduce batching interface jamal
2007-09-23 18:00 ` [PATCH 3/4][NET_BATCH] net core use batching jamal
2007-09-23 18:02 ` [ofa-general] [PATCH 4/4][NET_SCHED] kill dev->gso_skb jamal
2007-09-30 18:53 ` [ofa-general] [PATCH 3/3][NET_SCHED] " jamal
2007-10-07 18:39 ` [ofa-general] [PATCH 3/3][NET_BATCH] " jamal
2007-09-30 18:52 ` [ofa-general] [PATCH 2/3][NET_BATCH] net core use batching jamal
2007-10-01 4:11 ` Bill Fink
2007-10-01 13:30 ` jamal
2007-10-02 4:25 ` [ofa-general] " Bill Fink
2007-10-02 13:20 ` jamal
2007-10-03 5:29 ` [ofa-general] " Bill Fink
2007-10-03 13:42 ` jamal
2007-10-01 10:42 ` [ofa-general] " Patrick McHardy
2007-10-01 13:21 ` jamal
2007-10-08 5:03 ` Krishna Kumar2
2007-10-08 13:17 ` jamal
2007-10-09 3:09 ` [ofa-general] " Krishna Kumar2
2007-10-09 13:10 ` jamal
2007-10-07 18:38 ` [ofa-general] " jamal
2007-09-30 18:51 ` [ofa-general] [PATCH 1/4] [NET_BATCH] Introduce batching interface jamal
2007-09-30 18:54 ` [ofa-general] Re: [PATCH 1/3] " jamal
2007-10-07 18:36 ` [ofa-general] " jamal
2007-10-08 9:59 ` Krishna Kumar2
2007-10-08 13:49 ` jamal
2007-09-24 19:12 ` [ofa-general] RE: [PATCH 1/4] [NET_SCHED] explict hold dev tx lock Waskiewicz Jr, Peter P
2007-09-24 22:51 ` jamal
2007-09-24 22:57 ` Waskiewicz Jr, Peter P
2007-09-24 23:38 ` [ofa-general] " jamal
2007-09-24 23:47 ` Waskiewicz Jr, Peter P
2007-09-25 0:14 ` [ofa-general] " Stephen Hemminger
2007-09-25 0:31 ` [ofa-general] " Waskiewicz Jr, Peter P
2007-09-25 13:15 ` [ofa-general] " jamal
2007-09-25 15:24 ` Stephen Hemminger
2007-09-25 22:14 ` jamal
2007-09-25 22:43 ` jamal
2007-09-25 13:08 ` [ofa-general] " jamal
2007-10-08 4:51 ` [ofa-general] " David Miller
2007-10-08 13:34 ` jamal
2007-10-08 14:22 ` parallel networking (was Re: [PATCH 1/4] [NET_SCHED] explict hold dev tx lock) Jeff Garzik
2007-10-08 15:18 ` [ofa-general] " jamal
2007-10-08 21:11 ` [ofa-general] Re: parallel networking David Miller
2007-10-08 22:30 ` jamal
2007-10-08 22:33 ` David Miller
2007-10-08 22:35 ` [ofa-general] " Waskiewicz Jr, Peter P
2007-10-08 23:42 ` [ofa-general] " jamal
2007-10-09 1:53 ` Jeff Garzik
2007-10-09 14:59 ` Michael Krause
2007-10-08 21:05 ` [PATCH 1/4] [NET_SCHED] explict hold dev tx lock David Miller
2007-09-23 18:19 ` [PATCHES] TX batching Jeff Garzik
2007-09-23 19:11 ` [ofa-general] " jamal
2007-09-23 19:36 ` Kok, Auke
2007-09-23 21:20 ` jamal
2007-09-24 7:00 ` Kok, Auke
2007-09-24 22:38 ` jamal
2007-09-24 22:52 ` [ofa-general] " Kok, Auke
2007-09-24 22:54 ` [DOC] Net batching driver howto jamal
2007-09-25 20:16 ` [ofa-general] " Randy Dunlap
2007-09-25 22:28 ` jamal
2007-09-25 0:15 ` [PATCHES] TX batching Jeff Garzik
2007-09-30 18:50 ` [ofa-general] " jamal
2007-09-30 19:19 ` [ofa-general] " jamal
2007-10-07 18:34 ` [ofa-general] " jamal
2007-10-08 12:51 ` [ofa-general] " Evgeniy Polyakov
2007-10-08 14:05 ` jamal
2007-10-09 8:14 ` Krishna Kumar2
2007-10-09 13:25 ` jamal
2007-09-17 4:08 ` [PATCH 0/10 REV5] Implement skb batching and support in IPoIB/E1000 Krishna Kumar2
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20070914113709.80baba4d.randy.dunlap@oracle.com \
--to=randy.dunlap@oracle$(echo .)com \
--cc=Robert.Olsson@data$(echo .)slu.se \
--cc=davem@davemloft$(echo .)net \
--cc=gaagaan@gmail$(echo .)com \
--cc=general@lists$(echo .)openfabrics.org \
--cc=hadi@cyberus$(echo .)ca \
--cc=herbert@gondor$(echo .)apana.org.au \
--cc=jagana@us$(echo .)ibm.com \
--cc=jeff@garzik$(echo .)org \
--cc=johnpol@2ka$(echo .)mipt.ru \
--cc=kaber@trash$(echo .)net \
--cc=krkumar2@in$(echo .)ibm.com \
--cc=kumarkr@linux$(echo .)ibm.com \
--cc=mcarlson@broadcom$(echo .)com \
--cc=mchan@broadcom$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=peter.p.waskiewicz.jr@intel$(echo .)com \
--cc=rdreier@cisco$(echo .)com \
--cc=shemminger@linux-foundation$(echo .)org \
--cc=sri@us$(echo .)ibm.com \
--cc=tgraf@suug$(echo .)ch \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox