melnikovsky at mail
Mar 4, 2008, 2:27 PM
Views: 2821
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ehci-hcd affects hda speed
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Hi,
I have recently installed a VT6212L-based PCI USB controller into my old
rock-stable P3B-F computer just to discover that, even being idle, it
significantly slows down main PATA hard drive. I have found an earlier
thread with similar (?) problem (archived at http://marc.info/?t=111749614000002&r=1&w=2 )
but it provides no solution. Can this behaviour be explained? Can it be fixed?
There's one thing that makes me optimistic: USB traffic _speeds_up_ hda.
That is hdparm gives ~20% improvement in buffered reads if a USB flash is
inserted and another xterm simultaneously runs
# dd if=/dev/sda of=/dev/null bs=1024
Here's what I see:
------------------------------------------------------------------------------
# hdparm -t -T /dev/hda
/dev/hda:
Timing cached reads: 312 MB in 2.01 seconds = 155.60 MB/sec
Timing buffered disk reads: 88 MB in 3.06 seconds = 28.77 MB/sec
# modprobe ehci-hcd
# hdparm -t -T /dev/hda
/dev/hda:
Timing cached reads: 274 MB in 2.01 seconds = 136.58 MB/sec
Timing buffered disk reads: 44 MB in 3.10 seconds = 14.20 MB/sec
# rmmod ehci-hcd
# hdparm -t -T /dev/hda
/dev/hda:
Timing cached reads: 286 MB in 2.01 seconds = 142.48 MB/sec
Timing buffered disk reads: 90 MB in 3.06 seconds = 29.44 MB/sec
------------------------------------------------------------------------------
And here's what I have (kernel 2.6.24.3):
------------------------------------------------------------------------------
#lspci -v
00:09.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 62) (prog-if 00 [UHCI])
Subsystem: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller
Flags: medium devsel, IRQ 5
I/O ports at d000 [size=32]
Capabilities: [80] Power Management version 2
00:09.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 62) (prog-if 00 [UHCI])
Subsystem: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller
Flags: medium devsel, IRQ 9
I/O ports at b800 [size=32]
Capabilities: [80] Power Management version 2
00:09.2 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 65) (prog-if 20 [EHCI])
Subsystem: VIA Technologies, Inc. USB 2.0
Flags: bus master, medium devsel, latency 32, IRQ 11
Memory at d3800000 (32-bit, non-prefetchable) [size=256]
Capabilities: [80] Power Management version 2
# cat /proc/interrupts
CPU0
0: 100814528 XT-PIC-XT timer
1: 4057 XT-PIC-XT i8042
2: 0 XT-PIC-XT cascade
3: 1013 XT-PIC-XT
4: 2 XT-PIC-XT
5: 7165568 XT-PIC-XT bttv0, FM801, uhci_hcd:usb2, uhci_hcd:usb3
8: 25956003 XT-PIC-XT
9: 661413 XT-PIC-XT eth1, uhci_hcd:usb4
10: 4 XT-PIC-XT
11: 13526145 XT-PIC-XT eth0, ehci_hcd:usb1
12: 1068179 XT-PIC-XT i8042
14: 710123 XT-PIC-XT ide0
15: 4365 XT-PIC-XT ide1
NMI: 0 Non-maskable interrupts
TRM: 0 Thermal event interrupts
SPU: 0 Spurious interrupts
ERR: 0
------------------------------------------------------------------------------
Please let me know if I missed something important.
Thanks
-L
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ehci-hcd affects hda speed
