On Tue, 12 Jul 2005, vitko wrote: > > I don't understand that at all. If you rebuild the driver with debugging > > turned off, does the throughput decrease again? (That is, was this caused > > by the rebuild itself or by the debugging code?) > > 2.6.12 usb-storage with debugging writes 1.4 MB/s, 2.6.12 non-debugging > usb-storage makes only cca 135 kb/s, each test was made after reboot with > respective kernel.
Yes, but was the non-debugging usb-storage one that you got from a distribution or did you compile it yourself? Have you tried comparing the write speeds of the two modules without rebooting in between? Just rmmod one and insmod the other. (Don't forget to unmount the filesystem while doing this!) > > The one obvious difference between the two logs is the lengths of the > > tranfers. With 2.6.11 the transfers were all 8192 bytes, and with 2.6.12 > > they were mostly 512 bytes with 2048 bytes occuring 1/4 of the time. > > This might be the result of a change in the filesystem layer. > > Huh. FYI filesystem used is FAT32. I vaguely recall hearing about some recent change in the block size used by FAT. Can't remember where. > > You could experiment with not using -o sync. Under 2.6.13-rc2 or later it > > may turn out to be just as reliable. > > I'd like to try, but sorry for my ignorance - how do I build rc2? So far > I always got full vanilla kernel from kernel.org. As 2.6.13-rc2 is only > patch, what kernel version should I get to apply this patch to? The patch is http://www.kernel.org/pub/linux/kernel/v2.6/testing/patch-2.6.13-rc2.bz2 and it applies against vanilla 2.6.12. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by the 'Do More With Dual!' webinar happening July 14 at 8am PDT/11am EDT. We invite you to explore the latest in dual core and dual graphics technology at this free one hour event hosted by HP, AMD, and NVIDIA. To register visit http://www.hp.com/go/dualwebinar _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
