* [Bloat] ADSL/ATM linklayer tc shaping regression fix commits for stable
@ 2013-08-20 11:26 Jesper Dangaard Brouer
2013-08-20 15:16 ` Greg Kroah-Hartman
0 siblings, 1 reply; 5+ messages in thread
From: Jesper Dangaard Brouer @ 2013-08-20 11:26 UTC (permalink / raw)
To: stable, Greg Kroah-Hartman
Cc: netdev, linux-kernel, bufferbloat-list, David Miller
Hi Greg (and google search),
ADSL/ATM linklayer shaping were broken in kernel release from 3.8 to
3.10 by commit 56b765b79 ("htb: improved accuracy at high rates").
I can see that 3.9-stable is marked EOL, and 3.8-stable also seems
closed. I guess it is up to Greg, how far the commits described below
can be backported. Below is the commit needed for a 3.9 backport.
This was not the only regression introduced by the regression commit,
several fixes were required:
(Refactor/change commit for easy 3.9 backport step (in v3.10-rc1)):
commit 6906f4ed6f8 (htb: add HTB_DIRECT_QLEN attribute)
The following commit fixes are in 3.10-rc5:
commit 01cb71d2d47 (net_sched: restore "overhead xxx" handling)
commit 5343a7f8be1 (net_sched: htb: do not mix 1ns and 64ns time units)
The following commit fixes are in 3.10-rc6:
commit 40edeff6e1c (net_sched: qdisc_get_rtab() must check data[] array)
(this fix goes further back, but needed for linklayer atm, see below[1])
Refactor improvements (v3.11-rc1):
commit 130d3d68b52 (net_sched: psched_ratecfg_precompute() improvements)
The linklayer ATM/ADSL fix, reached 3.11-rc6:
commit 8a8e3d84b17 (net_sched: restore "linklayer atm" handling)
[1] Eric Dumazet also found a general "linklayer atm" regression
(dating way-back), which could cause rate-tables to get wrongly shared
between the same rates with-and-without linklayer atm settings.
Addressed/fixed in (3.10-rc6:):
- commit 40edeff6e1c (net_sched: qdisc_get_rtab() must check data[] array)
When configuring two completely equal rates, the kernel detects that
these two equal rates can share the same rate-table. But the kernel
didn't check if the rate-table data had been modified, which is done
in the linklayer atm case.
In practice, this often isn't a problem, as overhead parameter is
usually combined with the linklayer parameter.
The regression commit 56b765b79 ("htb: improved accuracy at high
rates"), is not all bad, it did provided a significantly improved rate
shaping accuracy. The old rate-table based system, which this commit
removed, would get inaccurate at rates above 100Mbit/s.
(ps. I'm the original author of http://www.adsl-optimizer.dk/ and
http://sourceforge.net/projects/adsl-optimizer/)
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Sr. Network Kernel Developer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Bloat] ADSL/ATM linklayer tc shaping regression fix commits for stable
2013-08-20 11:26 [Bloat] ADSL/ATM linklayer tc shaping regression fix commits for stable Jesper Dangaard Brouer
@ 2013-08-20 15:16 ` Greg Kroah-Hartman
2013-08-21 12:03 ` Jesper Dangaard Brouer
0 siblings, 1 reply; 5+ messages in thread
From: Greg Kroah-Hartman @ 2013-08-20 15:16 UTC (permalink / raw)
To: Jesper Dangaard Brouer
Cc: netdev, linux-kernel, stable, bufferbloat-list, David Miller
On Tue, Aug 20, 2013 at 01:26:29PM +0200, Jesper Dangaard Brouer wrote:
> Hi Greg (and google search),
>
> ADSL/ATM linklayer shaping were broken in kernel release from 3.8 to
> 3.10 by commit 56b765b79 ("htb: improved accuracy at high rates").
>
> I can see that 3.9-stable is marked EOL, and 3.8-stable also seems
> closed. I guess it is up to Greg, how far the commits described below
> can be backported. Below is the commit needed for a 3.9 backport.
As you say, 3.8 and 3.9 are end-of-life, so there's nothing I can, or
even want, to do with them, sorry.
If there are issues with 3.10, that's a different story.
> Refactor improvements (v3.11-rc1):
> commit 130d3d68b52 (net_sched: psched_ratecfg_precompute() improvements)
>
> The linklayer ATM/ADSL fix, reached 3.11-rc6:
> commit 8a8e3d84b17 (net_sched: restore "linklayer atm" handling)
David sends me the networking patches for the stable tree, and if he
thinks these are applicable, then I'll take them.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Bloat] ADSL/ATM linklayer tc shaping regression fix commits for stable
2013-08-20 15:16 ` Greg Kroah-Hartman
@ 2013-08-21 12:03 ` Jesper Dangaard Brouer
2013-08-21 17:10 ` Dave Taht
2013-08-21 18:20 ` David Miller
0 siblings, 2 replies; 5+ messages in thread
From: Jesper Dangaard Brouer @ 2013-08-21 12:03 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: netdev, linux-kernel, stable, bufferbloat-list, David Miller
On Tue, 20 Aug 2013 08:16:50 -0700
Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> On Tue, Aug 20, 2013 at 01:26:29PM +0200, Jesper Dangaard Brouer wrote:
[...]
> If there are issues with 3.10, that's a different story.
>
> > Refactor improvements (v3.11-rc1):
> > commit 130d3d68b52 (net_sched: psched_ratecfg_precompute() improvements)
Needed because it fixes the accuracy of the rate calc.
> > The linklayer ATM/ADSL fix, reached 3.11-rc6:
> > commit 8a8e3d84b17 (net_sched: restore "linklayer atm" handling)
Needed because we broke userspace interface.
> David sends me the networking patches for the stable tree, and if he
> thinks these are applicable, then I'll take them.
DaveM, please? What do you want me to do, submit this req/patches somehow?
(Can see that is not currently on your stable queue via:
http://patchwork.ozlabs.org/bundle/davem/stable/?state=*)
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Sr. Network Kernel Developer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Bloat] ADSL/ATM linklayer tc shaping regression fix commits for stable
2013-08-21 12:03 ` Jesper Dangaard Brouer
@ 2013-08-21 17:10 ` Dave Taht
2013-08-21 18:20 ` David Miller
1 sibling, 0 replies; 5+ messages in thread
From: Dave Taht @ 2013-08-21 17:10 UTC (permalink / raw)
To: Jesper Dangaard Brouer
Cc: Greg Kroah-Hartman, linux-kernel, stable, netdev,
bufferbloat-list, David Miller
[-- Attachment #1: Type: text/plain, Size: 2123 bytes --]
On Wed, Aug 21, 2013 at 5:03 AM, Jesper Dangaard Brouer
<brouer@redhat.com>wrote:
>
> On Tue, 20 Aug 2013 08:16:50 -0700
> Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> > On Tue, Aug 20, 2013 at 01:26:29PM +0200, Jesper Dangaard Brouer wrote:
> [...]
>
> > If there are issues with 3.10, that's a different story.
> >
> > > Refactor improvements (v3.11-rc1):
> > > commit 130d3d68b52 (net_sched: psched_ratecfg_precompute()
> improvements)
>
> Needed because it fixes the accuracy of the rate calc.
>
> > > The linklayer ATM/ADSL fix, reached 3.11-rc6:
> > > commit 8a8e3d84b17 (net_sched: restore "linklayer atm" handling)
>
> Needed because we broke userspace interface.
>
> > David sends me the networking patches for the stable tree, and if he
> > thinks these are applicable, then I'll take them.
>
> DaveM, please? What do you want me to do, submit this req/patches somehow?
>
> (Can see that is not currently on your stable queue via:
> http://patchwork.ozlabs.org/bundle/davem/stable/?state=*)
>
>
+1 Dealing with the busted DSL stuff since 3.8 has been no fun and it would
be nice if these last fixes made it into 3.10.X at least so router/fw
distros can pick them up more easily. The difference in dsl behavior since
the bustage in 3.8 to the saner now is remarkable.
Probably not meeting the criteria for 3.10-stable inclusion (as they aren't
exactly bugfixes) are the tiny improvements to the flow dissector made in
3.11 for better ipip, ipv6 encapsulation, and 802.1ad support, but I
thought I'd mention them so other fq_codel folk pick them up that need them.
Not ready for any tree and increasingly doubtful for 3.12 are some
improvements under test to codel and cisco's sch_pie, if anyone wants to
play with them, let me know off list.
> --
> Best regards,
> Jesper Dangaard Brouer
> MSc.CS, Sr. Network Kernel Developer at Red Hat
> Author of http://www.iptv-analyzer.org
> LinkedIn: http://www.linkedin.com/in/brouer
>
--
Dave Täht
Fixing bufferbloat with cerowrt:
http://www.teklibre.com/cerowrt/subscribe.html
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Bloat] ADSL/ATM linklayer tc shaping regression fix commits for stable
2013-08-21 12:03 ` Jesper Dangaard Brouer
2013-08-21 17:10 ` Dave Taht
@ 2013-08-21 18:20 ` David Miller
1 sibling, 0 replies; 5+ messages in thread
From: David Miller @ 2013-08-21 18:20 UTC (permalink / raw)
To: brouer; +Cc: gregkh, linux-kernel, stable, netdev, bloat
From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Wed, 21 Aug 2013 14:03:50 +0200
>
> On Tue, 20 Aug 2013 08:16:50 -0700
> Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
>> On Tue, Aug 20, 2013 at 01:26:29PM +0200, Jesper Dangaard Brouer wrote:
> [...]
>
>> If there are issues with 3.10, that's a different story.
>>
>> > Refactor improvements (v3.11-rc1):
>> > commit 130d3d68b52 (net_sched: psched_ratecfg_precompute() improvements)
>
> Needed because it fixes the accuracy of the rate calc.
>
>> > The linklayer ATM/ADSL fix, reached 3.11-rc6:
>> > commit 8a8e3d84b17 (net_sched: restore "linklayer atm" handling)
>
> Needed because we broke userspace interface.
>
>> David sends me the networking patches for the stable tree, and if he
>> thinks these are applicable, then I'll take them.
>
> DaveM, please? What do you want me to do, submit this req/patches somehow?
>
> (Can see that is not currently on your stable queue via:
> http://patchwork.ozlabs.org/bundle/davem/stable/?state=*)
I'll put it there, you just have to formally ask me to do it that's
all.
Asking Greg to do it directly is a complete waste of time. :-)
^ permalink raw reply [flat|nested] 5+ messages in thread
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2013-08-20 11:26 [Bloat] ADSL/ATM linklayer tc shaping regression fix commits for stable Jesper Dangaard Brouer
2013-08-20 15:16 ` Greg Kroah-Hartman
2013-08-21 12:03 ` Jesper Dangaard Brouer
2013-08-21 17:10 ` Dave Taht
2013-08-21 18:20 ` David Miller
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