linaro-pkg team mailing list archive

[Ming Lei <709245@xxxxxxxxxxxxxxxxxx>]

On Fri, Jul 6, 2012 at 6:57 AM, Emeric Vigier <709245@xxxxxxxxxxxxxxxxxx> wrote:
> Hi,
>
> I am having ethernet performance issue on panda rev A3. TX gets stuck while RX seems fine. At least pinging is ok...

We are discussing a similar problem now, see below link:

            http://marc.info/?t=134145311800001&r=1&w=2

I found that enabling DEBUG_SLAB may degrade TX performance a lot( ~35Mbps).
But if the option is disabled, the TX performance should be OK(> 90Mbps).

I am not sure if it is same with your problem.


> I started a thread on various mailing-list (http://comments.gmane.org/gmane.linux.network/234335).
> I made a lot of trials but no luck so far...
>
> My problem may be related to the one described here for usb storage. My
> kernel already embeds Ming Lei's patch
> (https://patchwork.kernel.org/patch/1113332/), and
> CONFIG_ARM_DMA_MEM_BUFFERABLE and CONFIG_ARCH_HAS_BARRIERS are enabled.
> But still ethernet performance is really poor.
>
> Smsc9514 device driver relies on usbnet. I lack usb knowledge, thus I
> cannot state whether Ming Lei's patch in ehci-q.c "should" fix my issue

> if they were related. Otherwise, did anyone find out that
> CONFIG_PL310_ERRATA_769419 patch above effectively fixes the usb storage
> issue?

Yes, it is fine for the problem, so the ehci patch isn't needed to
upstream.


Thanks,
--
Ming Lei

-- 
You received this bug notification because you are a member of Linaro
Maintainers, which is the registrant for Linaro Linux.
https://bugs.launchpad.net/bugs/709245

Title:
  ARM SMP scheduler performance bug

Status in Linaro Ubuntu Evaluation Builds:
  Fix Released
Status in Linaro Linux:
  Fix Committed
Status in OEM Priority Project:
  Fix Released
Status in OEM Priority Project maverick series:
  Fix Released
Status in OEM Priority Project natty series:
  Fix Released
Status in OEM Priority Project oneiric series:
  Fix Released
Status in “linux-ti-omap4” package in Ubuntu:
  Fix Released
Status in “linux-ti-omap4” source package in Maverick:
  Fix Released
Status in “linux-ti-omap4” source package in Natty:
  Fix Released
Status in “linux-ti-omap4” source package in Oneiric:
  Fix Released

Bug description:
  Original Bug name: "panda: USB disk IO slow"

  This bug effects ARM Cortex A9 cores, snowball, nvidia, OMAP 4, and
  other Cortex A9 processors.  Problem is in Fedora ARM builds also so
  not limited to Ubuntu.

  My Panda's USB seems to be significantly slower than a Beagle C4.

  hdparm shows buffered reads as ~12MB/s on the Panda, and about ~20-25MB/s on a Beagle C4 from the same
  external Lacie USB disk.

  Kernel is 2.6.37-1002-linaro-omap

  Disk shows as:

  [    5.170440] scsi 0:0:0:0: Direct-Access     LaCie    d2 quadra             PQ: 0 ANSI: 4
  [    5.172546] sd 0:0:0:0: Attached scsi generic sg0 type 0
  [    5.175415] sd 0:0:0:0: [sda] 976773168 512-byte logical blocks: (500 GB/465 GiB)

  The board is otherwise idle during the test.

  Doing perf_2.6.37-12 record -a dd if=/dev/sda of=/dev/null bs=4096
  count=100000

  shows :
      81.41%         swapper  [kernel.kallsyms]     [k] default_idle
       6.33%              dd  [kernel.kallsyms]     [k] __copy_to_user
       0.94%         swapper  [kernel.kallsyms]     [k] cpu_idle
       0.51%              dd  [kernel.kallsyms]     [k] __make_request
       0.51%  perf_2.6.37-12  [kernel.kallsyms]     [k] __copy_from_user

  which suggests it's not CPU constrained.

  Dave

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