Re: [Bug 709245] Re: panda: USB disk IO slow
Hi, I think that the problem is caused by ehci driver instead of ARM SMP scheduler, and I have verified that patch below can fix the problem. And the patch has been posted on usb/arm/omap mail list for discussion. But I am wondering that why no such problem after passing 'nosmp' to kernel. From d85a08714ed23ec8688013b464dc90c6386db0d8 Mon Sep 17 00:00:00 2001 From: Ming Lei ming@canonical.com Date: Sat, 27 Aug 2011 22:29:15 +0800 Subject: [PATCH] usb: ehci: fix update qtd-token in qh_append_tds This patch fixs one performance bug on ARM Cortex A9 dual core platform, which has been reported on quite a few ARM machines(OMAP4, Tegra 2, snowball...), see details from link of https://bugs.launchpad.net/bugs/709245. In fact, one mb() on ARM is enough to flush L2 cache, but 'dummy-hw_token = token;' after mb() is added just for obeying correct mb() usage. The patch has been tested ok on OMAP4 panda A1 board, the performance of 'dd' over usb mass storage can be increased from 4~5MB/sec to 14~16MB/sec after applying this patch. Signed-off-by: Ming Lei ming@canonical.com --- drivers/usb/host/ehci-q.c | 14 ++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 0917e3a..65b5021 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -1082,6 +1082,20 @@ static struct ehci_qh *qh_append_tds ( wmb (); dummy-hw_token = token; + /* The mb() below is added to make sure that +* 'token' can be writen into qtd, so that ehci +* HC can see the up-to-date qtd descriptor. On +* some archs(at least on ARM Cortex A9 dual core), +* writing into coherenet memory doesn't mean the +* value written can reach physical memory +* immediately, and the value may be buffered +* inside L2 cache. 'dummy-hw_token = token;' +* after mb() is added for obeying correct mb() +* usage. +* */ + mb(); + token = dummy-hw_token; + urb-hcpriv = qh_get (qh); } } -- 1.7.4.1 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: ARM SMP scheduler performance bug To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Also affects: linux-ti-omap4 (Ubuntu Natty) Importance: Undecided Status: New ** Also affects: linux-ti-omap4 (Ubuntu Maverick) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Description changed: + Original Bug name: panda: USB disk IO slow + 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 LaCied2 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=10 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 - + 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 ** Summary changed: - panda: USB disk IO slow + ARM SMP scheduler performance bug -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: ARM SMP scheduler performance bug To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
I ran the tests again, with the noop, cfq and deadline I/O schedulers, and the results differed in interesting ways. See attached logs. ** Attachment added: noop test run 1 https://bugs.launchpad.net/linux-linaro/+bug/709245/+attachment/2256614/+files/speedtest-noop.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Attachment added: cfq test run 1 https://bugs.launchpad.net/linux-linaro/+bug/709245/+attachment/2256615/+files/speedtest-cfq.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Attachment added: deadline test run 1 https://bugs.launchpad.net/linux-linaro/+bug/709245/+attachment/2256616/+files/speedtest-deadline.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Attachment added: noop test run 2 https://bugs.launchpad.net/linux-linaro/+bug/709245/+attachment/2256617/+files/speedtest-noop%20%282%29.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Attachment added: cfq test run 2 https://bugs.launchpad.net/linux-linaro/+bug/709245/+attachment/2256618/+files/speedtest-cfq%20%282%29.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Attachment added: deadline test run 2 https://bugs.launchpad.net/linux-linaro/+bug/709245/+attachment/2256619/+files/speedtest-deadline%20%282%29.log -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Maybe the 1ms threshold thing is just to do with a threshold heuristic where it stops using the scheduler and sleeping and instead spins udelay() style, hence the 100% CPU. That's not to write off its effect on the bug just a possible explanation of why it cares about 1ms or less. Reading these new findings yesterday and today I wonder if it's somehow related to when the ehci stuff schedules the URB. Like if the CPU is totally up it can pack USB transactions to go out immediately, but somehow when idle, although what exactly is in what kind of idle is unclear, it bumps it to the next frame or so. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Can someone check does it happens on other multicore A9 board? Origen or Versatile Express (Snowball lacks usb host port). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Let me quote from #pandaboard: prpplague TheSeven: the direction the debugging is going is that this is a thread issue, i suspect that the .0099 is just under the thread timing prpplague TheSeven: linaro folks and fedora folks are working on debugging this prpplague TheSeven: it doesn't appear to be panda or omap4 specific prpplague TheSeven: it has been recreated on the snowball and on a tegra platform -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
I just tried the 3.0 kernel, and it behaves in exactly the same way. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
I tested some more today (Oneiric 3.0 kernel) and the external USB drive on a Panda. With nosmp passed on the boot command line, the throughput is good with or without the ping and about the same as using both cores and pinging it. Booting with both cores and putting cpu1 offline does not seem to affect the behaviour - pinging leads to 4x or 5x throughput over not-pinging. So it may be related to SMP scheduling. Also nosmp and putting one core offline at runtime is apparently not the same ( I naively thought it should be) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Tags added: iso-testing -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
I see the same behaviour without ethernet plugged in, and pinging the panda via wlan0. Is that chip too on the same USB controller? 5x speed increase on write when pinging with -i.0001 jani@panda:~$ time dd if=/dev/zero of=alma bs=4M count=1024 1024+0 records in 1024+0 records out 4294967296 bytes (4.3 GB) copied, 1451.47 s, 3.0 MB/s real25m7.935s user0m0.023s sys 1m24.266s jani@panda:~$ time dd if=/dev/zero of=alma2 bs=4M count=1024 1024+0 records in 1024+0 records out 4294967296 bytes (4.3 GB) copied, 267.908 s, 16.0 MB/s real4m30.361s user0m0.016s sys 1m15.844s -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Hi Jani - No, Panda WLAN is on a 4-bit SDIO interface. So it's completely different from ping on Ethernet, I don't know what that means that it still changes USB throughput. Also when I reproduced this via pinging ethernet, I only saw a 50% increase in throughput; maybe it's to do with the block size. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Guess what, this issue indeed seems to be completely unrelated to USB. Something similar is going on for SD card access (see Bug #787246), and accessing LAN/WLAN has only an indirect influence. Look at this: http://paste.ubuntu.com/656410/ Seems like the CPU entering sleep states or something similar is the culprit? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
Re: [Bug 709245] Re: panda: USB disk IO slow
On Mon, 1 Aug 2011, Michael Sparmann wrote: Guess what, this issue indeed seems to be completely unrelated to USB. Something similar is going on for SD card access (see Bug #787246), and accessing LAN/WLAN has only an indirect influence. Look at this: http://paste.ubuntu.com/656410/ Seems like the CPU entering sleep states or something similar is the culprit? Interesting. To confirm this, please add nohlt to your kernel cmdline string and retest. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
No noticable improvement: http://paste.ubuntu.com/656498/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
Re: [Bug 709245] Re: panda: USB disk IO slow
On Mon, 1 Aug 2011, Michael Sparmann wrote: No noticable improvement: http://paste.ubuntu.com/656498/ The nohlt argument prevents the idle power saving code from being called at all. So if that doesn't help the USB case either than it is unlikely that anything related to sleep modes. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Further testing points towards thread switching behavior being related:
Nothing running in parallel: 10MB/s at big block sizes
perl -e while (1) { }: 5MB/s
perl -e use Time::HiRes qw( usleep ); while (1) { usleep(1) }: 20-25MB/s
perl -e use Time::HiRes qw( nanosleep ); while (1) { nanosleep(1) }: 5-25MB/s
(varying widely over time)
perl -e use Thread qw( yield ); while (1) { yield }: 10-20MB/s
sudo ping -q -i.001 localhost: 25MB/s (consistently)
Note that the sleep variants only reach ~25% CPU load (as seen in top),
while the yield and ping variants use a full core.
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[Bug 709245] Re: panda: USB disk IO slow
I have added nohlt and seems no any changes wrt. usb storage performance. But the following test is interesting, just run a 'busy' in background and increas usb storage performance triple or 4 times, and killing the 'busy' task will make usb storage performance poor like before. see my test below: root@tom-panda:~# ifconfig loLink encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) root@tom-panda:~# dd if=/dev/sda iflag=direct of=/dev/null bs=128K count=32 32+0 records in 32+0 records out 4194304 bytes (4.2 MB) copied, 5.9715 s, 702 kB/s root@tom-panda:~# cat /proc/cmdline ro elevator=noop vram=32M mem=456M@0x8000 mem=512M@0xA000 root=UUID=a957f519-7a09-48d9- a60d-b15883901edf fixrtc quiet splash console=ttyO2,115200n8 serialtty=ttyO2 earlyprintk root@tom-panda:~# ./busy [1] 1183 root@tom-panda:~# cat busy #/bin/sh x=1 while [ true ] do x=$(( $x + 1 )) done root@tom-panda:~# dd if=/dev/sda iflag=direct of=/dev/null bs=128K count=32 32+0 records in 32+0 records out 4194304 bytes (4.2 MB) copied, 0.771301 s, 5.4 MB/s root@tom-panda:~# kill -9 1183 root@tom-panda:~# sleep 3 [1]+ Killed ./busy root@tom-panda:~# dd if=/dev/sda iflag=direct of=/dev/null bs=128K count=32 32+0 records in 32+0 records out 4194304 bytes (4.2 MB) copied, 3.40616 s, 1.2 MB/s -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Another interesting thing, enabling usbmon will increase performance a lot. root@tom-panda:~# dd if=/dev/sda iflag=direct of=/dev/null bs=128K count=32 32+0 records in 32+0 records out 4194304 bytes (4.2 MB) copied, 3.4598 s, 1.2 MB/s root@tom-panda:~# cat /sys/kernel/debug/usb/usbmon/1u /tmp/usbmon-1u [1] 1485 root@tom-panda:~# dd if=/dev/sda iflag=direct of=/dev/null bs=128K count=32 32+0 records in 32+0 records out 4194304 bytes (4.2 MB) copied, 0.795455 s, 5.3 MB/s root@tom-panda:~# dd if=/dev/sda iflag=direct of=/dev/null bs=128K count=32 32+0 records in 32+0 records out 4194304 bytes (4.2 MB) copied, 0.278628 s, 15.1 MB/s root@tom-panda:~# killall -9 cat [1]+ Killed cat /sys/kernel/debug/usb/usbmon/1u /tmp/usbmon-1u root@tom-panda:~# dd if=/dev/sda iflag=direct of=/dev/null bs=128K count=32 32+0 records in 32+0 records out 4194304 bytes (4.2 MB) copied, 5.0556 s, 830 kB/s root@tom-panda:~# dd if=/dev/sda iflag=direct of=/dev/null bs=128K count=32 32+0 records in 32+0 records out 4194304 bytes (4.2 MB) copied, 3.2009 s, 1.3 MB/s -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
When running just dd at 1MB block size, I get ~5.5MB/s. When running with sudo ping -q -i.0100 localhost in the background, ping causes 1% CPU load, and I get ~10MB/s at 1MB block size and these ping statistics: 6228 packets transmitted, 6227 received, 0% packet loss, time 97329ms rtt min/avg/max/mdev = 0.000/0.053/2.899/0.050 ms When running with sudo ping -q -i.0099 localhost in the background, ping causes 100% (one core) CPU load, and I get ~20MB/s at 1MB block size and these ping statistics: 10339 packets transmitted, 10337 received, 0% packet loss, time 93032ms rtt min/avg/max/mdev = 0.000/0.033/0.946/0.031 ms Now why does ping process about twice as many packets but use 100 times more CPU (and get better response times) when I reduce the delay by just one percent? There's something fishy going on here... -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Tags added: armel kernel-bug -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Also affects: linux-ti-omap4 (Ubuntu Oneiric) Importance: High Status: Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Changed in: linaro-ubuntu Milestone: None = 11.07 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Appears to still be a problem with 3.0.0-1: ... Threaded I/O Tester: pts/tiobench-1.1.0 [Test: Write - Size Per Thread: 32MB - Thread Count: 4] Test 1 of 4 Estimated Time Remaining: 4 Hours, 57 Minutes Estimated Test Run-Time: 28 Minutes Expected Trial Run Count: 4 Started Run 1 @ 16:35:46 Started Run 2 @ 16:36:28 PING-START Started Run 3 @ 16:37:06 Started Run 4 @ 16:37:17 [Std. Dev: 73.18%] Started Run 5 @ 16:37:28 [Std. Dev: 61.73%] Started Run 6 @ 16:37:39 [Std. Dev: 54.21%] PING-STOP Started Run 7 @ 16:37:50 [Std. Dev: 63.24%] Started Run 8 @ 16:38:31 [Std. Dev: 68.34%] Test Results: 3.686 3.746 16.491 16.656 16.796 16.874 3.349 3.933 Average: 10.19 MB/s ^C # uname -a Linux panda-qa1 3.0.0-1-omap4 #0~dd1d9db SMP PREEMPT Wed Jul 20 19:41:32 CEST 2011 armv7l armv7l armv7l GNU/Linux -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
I was able to reproduce this in Maverick as well. ** Attachment added: bonnie-maverick.html https://bugs.launchpad.net/ubuntu/+source/linux-ti-omap4/+bug/709245/+attachment/2221456/+files/bonnie-maverick.html -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linux-linaro/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
Would be good to check if you're able to reproduce this issue with the 3.0 based kernel. ** Also affects: linaro-ubuntu Importance: Undecided Status: New ** Changed in: linaro-ubuntu Status: New = Confirmed ** Changed in: linaro-ubuntu Importance: Undecided = High -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linaro-ubuntu/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
** Also affects: linux-ti-omap4 (Ubuntu) Importance: Undecided Status: New ** Changed in: linux-ti-omap4 (Ubuntu) Importance: Undecided = High ** Changed in: linux-ti-omap4 (Ubuntu) Status: New = Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linux-linaro/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 709245] Re: panda: USB disk IO slow
I have been able to reproduce this bug using bonnie++. The process I used was to install Oneiric using the netboot installer to an external USB SATA drive and boot with that as my root filesystem (SD only has bootloaders kernel). Steps to reproduce on a running system: On panda (no ping): sudo apt-get install bonnie++ bonnie++ -n 0 -m USB HD -q 1bonnie.csv After this runs, on a different system on the same network, start sudo ping -i 0.001 panda (assuming the panda is in the host lookup), then on the panda run: bonnie++ -n 0 -m USB HD with ping -q 1bonnie.csv This will produce the results attached (bonnie.csv). Bonnie.html is an html formatted version of the output (with non-run tests removed). ** Attachment added: bonnie.html https://bugs.launchpad.net/ubuntu/+source/linux-ti-omap4/+bug/709245/+attachment/2218631/+files/bonnie.html -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/709245 Title: panda: USB disk IO slow To manage notifications about this bug go to: https://bugs.launchpad.net/linux-linaro/+bug/709245/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
