#3 Throughput fall for USB storage

[Anonymous]

I have found a significant throughput fall on a communication with USB Compact Flash Reader (Sandisk)
when the preemptible patch is applied.

Transfer rate of read operation is about 100KB/s with the preemptible patch against 900KB/s when this patch is not applied.

Tested kernel version was 2.4.12 and 2.4.14 with XFS support and without SMP. Used platform was Celeron 333MHz on Intel 440BX motherboard.

Thanks

Vaclav
email: movac@seznam.cz

[Sander van Grieken]

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user_id=698180

I have experienced problems with USB as well. I use the
usb-storage module to access a portable harddisk (archos
jukebox)

When the preemptible kernel patch is applied, and I begin
transfer of a large file (both reading and writing), the system
locks up hard! This happens at a random point during transfer,
but I haven't managed to transfer more than 300MB before the
system locks up.

I haven't noticed any throughput changes though..

tested on

kernel : 2.4.20 (both +SMP and -SMP)

mobo : VIA 8235 chipset (UDMA 133)

proc : athlon xp 2000