imx6q-wandboard: Ethernet tx-queue timeouts when SATA is active

Duan Fugang-B38611 B38611 at freescale.com
Wed Oct 9 04:20:59 EDT 2013


I validated it on imx6q sabresd platform + Linux 3.12-rc2, and can reproduce the issue.
As you description for the issue generation condition:
	-	achieve up to 52 MBytes/s network throughput
	-	SATA is running with high throughput at the same time


1. Use iperf tool do the networking UDP tx throughput test:
Run the server at Apple MAC book: iperf -s -u
Run the client at imx6q sabresd platform: iperf -c 192.168.0.2 -t 200 -u -b 600M -i 1 &

There have print log:
root at freescale /mnt/src$ [ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec  55.0 MBytes   461 Mbits/sec
[  3]  1.0- 2.0 sec  55.7 MBytes   467 Mbits/sec
[  3]  2.0- 3.0 sec  55.7 MBytes   467 Mbits/sec
[  3]  3.0- 4.0 sec  55.3 MBytes   464 Mbits/sec
[  3]  4.0- 5.0 sec  55.5 MBytes   466 Mbits/sec
[  3]  5.0- 6.0 sec  55.5 MBytes   466 Mbits/sec
[  3]  6.0- 7.0 sec  55.5 MBytes   465 Mbits/sec
[  3]  7.0- 8.0 sec  55.5 MBytes   466 Mbits/sec
[  3]  8.0- 9.0 sec  55.5 MBytes   466 Mbits/sec
[  3]  9.0-10.0 sec  55.5 MBytes   466 Mbits/sec
[  3] 10.0-11.0 sec  55.5 MBytes   466 Mbits/sec
......

2. Mount sata sda1 to /mnt/src, and run the script to copy files:
  while [ true ]
  do
 	cat ./L3.0.35_4.0.0_130425_images_MX6/* > /dev/null
 	sync
	echo 3 >/proc/sys/vm/drop_caches
  done &

The file " L3.0.35_4.0.0_130425_images_MX6.tar.gz " size is 5.9 Gbytes.
root at freescale /mnt/src/L3.0.35_4.0.0_130425_images_MX6$ du -h
5.9G

There have print log:
[  3] 126.0-127.0 sec  0.00 Bytes  0.00 bits/sec
[  3] 127.0-128.0 sec  0.00 Bytes  0.00 bits/sec
[  3] 128.0-129.0 sec  9.94 MBytes  83.4 Mbits/sec
[  3] 129.0-130.0 sec  15.3 MBytes   128 Mbits/sec
[  3] 130.0-131.0 sec  0.00 Bytes  0.00 bits/sec
[  3] 131.0-132.0 sec  0.00 Bytes  0.00 bits/sec
[  3] 132.0-133.0 sec  7.94 MBytes  66.6 Mbits/sec
[  3] 133.0-134.0 sec  29.0 MBytes   243 Mbits/sec
[  3] 134.0-135.0 sec  28.9 MBytes   243 Mbits/sec
[  3] 135.0-136.0 sec  29.1 MBytes   244 Mbits/sec
[  3] 136.0-137.0 sec  29.0 MBytes   243 Mbits/sec
[  3] 137.0-138.0 sec  29.0 MBytes   243 Mbits/sec
[  3] 138.0-139.0 sec  29.0 MBytes   243 Mbits/sec
[  3] 139.0-140.0 sec  29.0 MBytes   243 Mbits/sec
[  3] 140.0-141.0 sec  29.0 MBytes   243 Mbits/sec
[  3] 141.0-142.0 sec  29.0 MBytes   244 Mbits/sec
[  3] 142.0-143.0 sec  29.0 MBytes   243 Mbits/sec
[  3] 143.0-144.0 sec  29.0 MBytes   244 Mbits/sec
[  3] 144.0-145.0 sec  29.0 MBytes   243 Mbits/sec
....
The later, performance stay at 243Mbps.....


3. So the issue can be reproduced at Linux 3.12-rc2, I will dig out the root cause.


Thanks,
Andy


From: Thomas Scheiblauer <tom at sharkbay.at>
Data: Tuesday, October 08, 2013 5:58 PM
> To: Zhu Richard-R65037
> Cc: Li Frank-B20596; shawn.guo at linaro.org; linux-arm-
> kernel at lists.infradead.org
> Subject: Re: imx6q-wandboard: Ethernet tx-queue timeouts when SATA is
> active
> 
> I just figured out that it is probably NOT a power supply problem. I just
> connected a power supply which would a allow for up to 40A current and a
> stable voltage (btw, the Wandboard never consumed more than 0.8A during
> the tests) and the problems was still there.
> 
> Regards,
> Tom
> 
> On Die, 2013-10-08 at 11:31 +0200, Thomas Scheiblauer wrote:
> > Now (having both netcat streams running) I'm additionally getting
> > these message blocks in dmesg from time to time:
> >
> > [ 8338.755015] ata1.00: exception Emask 0x10 SAct 0x0 SErr 0x280100
> > action 0x6 frozen [ 8338.761322] ata1.00: irq_stat 0x08000000,
> > interface fatal error [ 8338.765953] ata1: SError: { UnrecovData 10B8B
> > BadCRC } [ 8338.769819] ata1.00: failed command: READ DMA EXT [
> > 8338.773242] ata1.00: cmd 25/00:00:c8:f2:44/00:01:19:00:00/e0 tag 0
> > dma 131072 in
> >          res 50/00:00:c7:f2:44/00:01:19:00:00/e0 Emask 0x10 (ATA bus
> > error)
> > [ 8338.786051] ata1.00: status: { DRDY } [ 8338.788435] ata1: hard
> > resetting link [ 8339.139781] ata1: SATA link up 3.0 Gbps (SStatus 123
> > SControl 300) [ 8339.146007] ata1.00: configured for UDMA/133 [
> > 8339.149856] ata1: EH complete
> >
> > Regards,
> > Tom
> >
> > On Die, 2013-10-08 at 11:02 +0200, Thomas Scheiblauer wrote:
> > > Hello Richard,
> > >
> > > To still make the problem happen every few seconds I additionally
> > > (in parallel to the /dev/sda stream) started a second netcat pipe
> > > pushing just /dev/zero to a different UDP port on the server like that:
> > > Server: nc -l -u -p 13000 > /dev/null
> > > Wandboard: nc -u <server> 13000 < /dev/zero
> > >
> > > That way I achieve up to 52 MBytes/s going out on the network
> interface.
> > >
> > > So the quantity of the network drops definitely increases when the
> > > network throughput gets higher.
> > >
> > > But still this only happens when SATA is running with high
> > > throughput at the same time. Only streaming date from /dev/zero over
> > > the net with 52 MBytes/s does not trigger the network interruptions.
> > >
> > > Regards,
> > > Tom
> > >
> > > On Die, 2013-10-08 at 08:50 +0200, Thomas Scheiblauer wrote:
> > > > Hello Richard,
> > > >
> > > > Thank you for looking into this.
> > > > The problem seems only to happen when the SATA and network
> > > > bandwidths are pushed up to their limits and the data throughput
> > > > is around 40 MBytes/s.
> > > > On the latest kernel from (with rmk/for-next, libata/for-next and
> > > > the RobertCNelson patchset merged in) I seem not to be able to
> > > > reach that throughput using NFS or netcat over TCP. The only
> > > > method I can reproduce this reliably now is to pipe through netcat
> using UDP.
> > > >
> > > > Please try to pipe /dev/sda through netcat like that:
> > > > on some (fast) server:
> > > > 	nc -l -u -p 12000 > /dev/null
> > > > on the Wnadboard:
> > > > 	nc -u <server-ip> 12000 < /dev/sda
> > > >
> > > > Though it does not happen so often at the moment as it seems the
> > > > latest changes to the kernel (maybe the libata/for-next merge?) do
> > > > not let me reach the previously possible throughput so easily. And
> > > > it seems to get more stable the longer it runs (thermal or power
> > > > supply problems???)
> > > >
> > > > Regards,
> > > > Tom
> > > >
> > > > On Die, 2013-10-08 at 03:19 +0000, Zhu Richard-R65037 wrote:I
> > > > validated the SATA functions on v3.12-rc3 of linus git repos just
> now.
> > > > >
> > > > >
> > > > > Here is the log:
> > > > > ...[v3.12-rc3 of linus repos]...
> > > > > Starting kernel ...
> > > > >
> > > > > Booting Linux on physical CPU 0x0 Linux version 3.12.0-rc3
> > > > > (richard at richard-OptiPlex-780) (gcc version 4.6.1 (Ubuntu/Linaro
> > > > > 4.6.1-9ubuntu3) ) #3 SMP Tue Oct 8 11:10:51 CST 2013
> > > > > CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c53c7d
> > > > > CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing
> > > > > instruction cache
> > > > > Machine: Freescale i.MX6 Quad/DualLite (Device Tree), model:
> > > > > Freescale i.MX6 Quad SABRE Smart Device Board ...
> > > > > ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
> > > > > ata1.00: ATA-8: SanDisk SSD P4 32GB, SSD 8.00, max UDMA/133
> > > > > ata1.00: 62533296 sectors, multi 1: LBA48
> > > > > ata1.00: configured for UDMA/133
> > > > > scsi 0:0:0:0: Direct-Access     ATA      SanDisk SSD P4 3 SSD  PQ:
> 0 ANSI: 5
> > > > > sd 0:0:0:0: [sda] 62533296 512-byte logical blocks: (32.0
> > > > > GB/29.8 GiB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0:
> > > > > [sda] Write cache: enabled, read cache: enabled, doesn't support
> > > > > DPO or FUA
> > > > >  sda: sda1 sda2
> > > > > sd 0:0:0:0: [sda] Attached SCSI disk ...[NFS]...
> > > > > mmcblk1rpmb: mmc2:0001 SEM08G partition 3 128 KiB
> > > > >  mmcblk1: p1 p2
> > > > > libphy: 2188000.ethernet:01 - Link is Up - 100/Full
> > > > > IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready Sending
> > > > > DHCP requests ., OK
> > > > > IP-Config: Got DHCP answer from 10.192.242.252, my address is
> > > > > 10.192.242.95
> > > > > IP-Config: Complete:
> > > > >      device=eth0, hwaddr=00:04:9f:02:18:df, ipaddr=10.192.242.95,
> mask=255.255.255.0, gw=10.192.242.254
> > > > >      host=10.192.242.95, domain=ap.freescale.net, nis-domain=(none)
> > > > >      bootserver=0.0.0.0, rootserver=10.192.225.216, rootpath=
> > > > >      nameserver0=10.192.130.201, nameserver1=10.211.0.3,
> > > > > nameserver2=10.196.51.200 ALSA device list:
> > > > >   #0: wm8962-audio
> > > > > ...[DO-MASS-DATA-COPY]...
> > > > > root at freescale ~$ cp -rf *.* /mnt/src/ root at freescale ~$ df
> > > > > Filesystem           1K-blocks      Used Available Use% Mounted on
> > > > > 10.192.225.216:/home/r65037/nfs/rootfs_mx5x_10.11
> > > > >                      843113892 781000276  19285936  98% /
> > > > > devtmpfs                385392        48    385344   0% /dev
> > > > > tmpfs                   385392        48    385344   0% /dev
> > > > > shm                     385392         0    385392   0% /dev/shm
> > > > > rwfs                       512         0       512   0% /mnt/rwfs
> > > > > /dev/sda1             14239124   1265124  12250676   9% /mnt/src
> > > > >
> > > > > Best Regards
> > > > > Richard Zhu
> > > > >
> > > > >
> > > > > -----Original Message-----
> > > > > From: Zhu Richard-R65037
> > > > > Sent: Tuesday, October 08, 2013 10:53 AM
> > > > > To: 'Thomas Scheiblauer'; linux-arm-kernel at lists.infradead.org
> > > > > Cc: Li Frank-B20596; shawn.guo at linaro.org
> > > > > Subject: RE: imx6q-wandboard: Ethernet tx-queue timeouts when
> > > > > SATA is active
> > > > >
> > > > > Hi Tom:
> > > > > Thanks for your reminder.
> > > > >
> > > > > Based on libata/for-next branch of Tejun's git
> > > > > repos(https://git.kernel.org/cgit/linux/kernel/git/tj/libata.git
> > > > > /), I used to verify the i.MX6Q SATA functions on i.MX6Q SD
> > > > > board + NFS enviroment.
> > > > > There is no such kind of issue.
> > > > >
> > > > > Let me re-validate it on the v3.12-rc3 of Linus' git repos.
> > > > >
> > > > > BTW, what’s the tool-chains used by you?
> > > > >
> > > > > Here is my logs:
> > > > > Booting Linux on physical CPU 0x0 Linux version 3.12.0-rc1+
> > > > > (richard at richard-OptiPlex-780) (gcc version 4.6.1 (Ubuntu/Linaro
> > > > > 4.6.1-9ubuntu3) ) #2 SMP Fri Sep 27 15:21:49 CST 2013
> > > > > CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7),
> cr=10c53c7d ...
> > > > > IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready Sending
> > > > > DHCP requests ., OK
> > > > > IP-Config: Got DHCP answer from 10.192.242.252, my address is
> > > > > 10.192.242.95
> > > > > IP-Config: Complete:
> > > > >      device=eth0, hwaddr=00:04:9f:02:18:df, ipaddr=10.192.242.95,
> mask=255.255.255.0, gw=10.192.242.254
> > > > >      host=10.192.242.95, domain=ap.freescale.net, nis-domain=(none)
> > > > >      bootserver=0.0.0.0, rootserver=10.192.225.216, rootpath=
> > > > >      nameserver0=10.192.130.201, nameserver1=10.211.0.3,
> nameserver2=10.196.51.200 ALSA device list:
> > > > >   #0: wm8962-audio
> > > > > ...
> > > > > root at freescale ~$ fdisk /dev/sda -l
> > > > >
> > > > > Disk /dev/sda: 32.0 GB, 32017047552 bytes
> > > > > 255 heads, 63 sectors/track, 3892 cylinders Units = cylinders of
> > > > > 16065 * 512 = 8225280 bytes
> > > > >
> > > > >    Device Boot      Start         End      Blocks  Id System
> > > > > /dev/sda1              92        1892    14466532+ 83 Linux
> > > > > /dev/sda2            1893        3892    16065000  83 Linux
> > > > > ...
> > > > > root at freescale ~$ cp -rf *.* /mnt/src/ root at freescale ~$ df ...
> > > > > shm                     385392         0    385392   0% /dev/shm
> > > > > rwfs                       512         0       512   0% /mnt/rwfs
> > > > > /dev/sda1             14239124    477484  13038316   4% /mnt/src
> > > > >
> > > > > Best Regards
> > > > > Richard Zhu
> > > > >
> > > > > -----Original Message-----
> > > > > From: Thomas Scheiblauer [mailto:tom at sharkbay.at]
> > > > > Sent: Sunday, October 06, 2013 6:01 PM
> > > > > To: linux-arm-kernel at lists.infradead.org
> > > > > Cc: Zhu Richard-R65037; Li Frank-B20596; shawn.guo at linaro.org
> > > > > Subject: BUG: imx6q-wandboard: Ethernet tx-queue timeouts when
> > > > > SATA is active
> > > > >
> > > > > I experience transmit queue timeouts every few seconds on the
> ethernet port when SATA is transfering data at the same time e.g. when
> copying from HD over NFS or piping HD data through ssh or netcat.
> > > > > When the first timeout happens I get this kernel message:
> > > > >
> > > > > WARNING: CPU: 2 PID: 0 at net/sched/sch_generic.c:264
> > > > > dev_watchdog
> > > > > +0x278/0x298()
> > > > > NETDEV WATCHDOG: eth0 (fec): transmit queue 0 timed out Modules
> > > > > linked in: uio_pdrv_genirq uio
> > > > > CPU: 2 PID: 0 Comm: swapper/2 Not tainted 3.12.0-rc3 #1
> > > > > Backtrace:
> > > > > [<80011a94>] (dump_backtrace+0x0/0x10c) from [<80011c30>]
> > > > > (show_stack
> > > > > +0x18/0x1c)
> > > > >  r6:00000108 r5:00000009 r4:00000000 r3:00000000 [<80011c18>]
> > > > > (show_stack+0x0/0x1c) from [<804b4418>] (dump_stack
> > > > > +0x78/0x94)
> > > > > [<804b43a0>] (dump_stack+0x0/0x94) from [<800228b4>]
> > > > > (warn_slowpath_common+0x6c/0x90)
> > > > >  r4:ef0b9e18 r3:8062f4b4
> > > > > [<80022848>] (warn_slowpath_common+0x0/0x90) from [<8002297c>]
> > > > > (warn_slowpath_fmt+0x38/0x40)
> > > > >  r8:80661e48 r7:806340c0 r6:ef353100 r5:ef368800 r4:00000000
> > > > > [<80022944>] (warn_slowpath_fmt+0x0/0x40) from [<803f3660>]
> > > > > (dev_watchdog+0x278/0x298)
> > > > >  r3:ef368800 r2:805cec10
> > > > > [<803f33e8>] (dev_watchdog+0x0/0x298) from [<8002c62c>]
> > > > > (call_timer_fn.isra.24+0x2c/0x8c)
> > > > >  r8:ef034814 r7:806340c0 r6:803f33e8 r5:00000100
> > > > > r4:ef0b8000After it [<8002c600>]
> > > > > (call_timer_fn.isra.24+0x0/0x8c) from [<8002c804>]
> > > > > (run_timer_softirq+0x178/0x200)
> > > > >  r7:806340c0 r6:00200200 r5:00000000 r4:ef0b9e90 [<8002c68c>]
> > > > > (run_timer_softirq+0x0/0x200) from [<800265d4>]
> > > > > (__do_softirq+0xf4/0x1e0)
> > > > > [<800264e0>] (__do_softirq+0x0/0x1e0) from [<80026a04>]
> > > > > (irq_exit
> > > > > +0xa0/0xf0)
> > > > > [<80026964>] (irq_exit+0x0/0xf0) from [<8000ef7c>] (handle_IRQ
> > > > > +0x44/0x9c)
> > > > >  r4:8062fd88 r3:00000180
> > > > > [<8000ef38>] (handle_IRQ+0x0/0x9c) from [<800084d4>]
> > > > > (gic_handle_irq
> > > > > +0x30/0x64)
> > > > >  r6:ef0b9f70 r5:8063a778 r4:f400010c r3:000000a0 [<800084a4>]
> > > > > (gic_handle_irq+0x0/0x64) from [<80012700>] (__irq_svc
> > > > > +0x40/0x50)
> > > > > Exception stack(0xef0b9f70 to 0xef0b9fb8)
> > > > > 9f60:                                     81e1e970 00000000
> 00574db0
> > > > > 00000000
> > > > > 9f80: 80661d47 00000001 80661d47 8063a3e0 804badbc ef0b8000
> > > > > 8063a388
> > > > > ef0b9fc4
> > > > > 9fa0: ef0b9fc8 ef0b9fb8 8000f184 8000f188 600e0013 ffffffff
> > > > >  r7:ef0b9fa4 r6:ffffffff r5:600e0013 r4:8000f188 [<8000f158>]
> > > > > (arch_cpu_idle+0x0/0x38) from [<80057814>]
> > > > > (cpu_startup_entry+0x68/0x138)
> > > > > [<800577ac>] (cpu_startup_entry+0x0/0x138) from [<80013578>]
> > > > > (secondary_start_kernel+0xd4/0xe8)
> > > > >  r7:806621f4 r3:00000005
> > > > > [<800134a4>] (secondary_start_kernel+0x0/0xe8) from [<100085a4>]
> > > > > (0x100085a4)
> > > > >  r4:7f09c06a r3:8000858c
> > > > > ---[ end trace db3ced4bf31e8711 ]---
> > > > >
> > > > > I tried with kernels 3.11.1, 3.12.0-rc2 and 3.12.0-rc3, vanilla as
> well as with all ARM fixes from rmk/for-next and the RobertCNelson
> patchset applied.
> > > > >
> > > > > Steps to reproduce:
> > > > >      1. boot one of the mentioned kernel releases (either patched
> or
> > > > >         unpatched)
> > > > >      2. copy some file from a storage device connected to the
> Quad's
> > > > >         SATA port (or just /dev/sda if sda is your SATA storage)
> over
> > > > >         the network to another machine either using nfs or piping
> > > > >         through ssh (use the HPN patched ssh and its "None" cipher
> to
> > > > >         make it fast because I suspect it happens more often when
> > > > >         copying with high throughput) or just pipe it directly
> through a
> > > > >         network socket (preferably UDP because it's faster) using
> e.g.
> > > > >         "netcat" (nc),
> > > > >      3. Look at the network throughput using e.g. "dstat" and at
> dmesg
> > > > >      4. network throughput will drop to zero every few seconds
> (seldom
> > > > >         it keeps stable for more tan 30 seconds) and will take
> about 3
> > > > >         or 4 seconds to recover.
> > > > >      5. additionally you may spot the above mentioned kernel
> warning
> > > > >         once in dmesg.
> > > > >      6. In addition when you use nfs (nfs4 server on the Wandboard
> in my
> > > > >         case) you will spot messages like this in dmesg every time
> a
> > > > >         throughput drop happens: "rpc-srv/tcp: nfsd: sent only
> 118848
> > > > >         when sending 262208 bytes - shutting down socket"
> > > > >
> > > > > The drops ONLY happen when using SATA at the same time as ethernet.
> If you just copy e.g. /dev/zero or some data from the SD-Card (testet with
> the internal SD) it will constantly run with about 408 MBit/s without
> interruptions.
> > > > >
> > > > > I have posted my current kernel config to
> > > > > ftp://ftp.arm.linux.org.uk/pub/linux/arm/incoming/tom.sharkbay.a
> > > > > t_config-3.12.0-rc3 I have already tried many different
> > > > > configurations regarding IO-schedulers, preemption models,
> dynticks, static ticks, etc...
> > > > >
> > > > > Btw, I'm running ArchLinux on the Wandboard and tried ext4 and
> > > > > btrfs filesystems on the SATA HD (it seems not to be a
> > > > > filesystem problem since it also happens when just copying
> > > > > /dev/sda)
> > > > >
> > > > > Regards,
> > > > > Tom
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > > linux-arm-kernel mailing list
> > > > > linux-arm-kernel at lists.infradead.org
> > > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> > > >
> > > >
> > > > _______________________________________________
> > > > linux-arm-kernel mailing list
> > > > linux-arm-kernel at lists.infradead.org
> > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> > >
> > >
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> >
> >
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