On Tue, 3 May 2005, Hendrik Muhs wrote: > Hello, > > the transfer speed is still to slow, on other systems I get 15-20 MB/s. > > Anyway, I compiled in debug messages again, and I it seems that the following > message correlates with the interrupts/pauses: > > usb-storage: *** thread sleeping. > usb-storage: queuecommand called > usb-storage: *** thread awakened. > > So my quesiton: what can cause this? What can make the thread sleep so long?
Your impression could be an illusion, since those three messages appear between every pair of commands. As for how long it sleeps -- I can't say anything about that because your log doesn't include any timestamps, so there's no way to know how long it actually slept for. Normally those periods would be very short. In general, the thread will sleep until the next command arrives and the scheduler wakes it up. So there's two separate things involved: how long before the next command, and what is the scheduler doing? If you don't have any other active processes running then the usb-storage thread should wake up right away. > Sorry I am not an expert on low-level driver stuff, so if anybody could > enlighten me, please do. > > A more complete log: > > usb-storage: *** thread sleeping. > usb-storage: queuecommand called > usb-storage: *** thread awakened. > usb-storage: Command WRITE_10 (10 bytes) > usb-storage: 2a 00 00 00 10 f7 00 00 08 00 > usb-storage: Bulk Command S 0x43425355 T 0x3735 L 4096 F 0 Trg 0 LUN 0 CL 10 > usb-storage: usb_stor_bulk_transfer_buf: xfer 31 bytes > usb-storage: Status code 0; transferred 31/31 > usb-storage: -- transfer complete > usb-storage: Bulk command transfer result=0 > usb-storage: usb_stor_bulk_transfer_sglist: xfer 4096 bytes, 1 entries > usb-storage: Status code 0; transferred 4096/4096 > usb-storage: -- transfer complete > usb-storage: Bulk data transfer result 0x0 > usb-storage: Attempting to get CSW... > usb-storage: usb_stor_bulk_transfer_buf: xfer 13 bytes > usb-storage: Status code 0; transferred 13/13 > usb-storage: -- transfer complete > usb-storage: Bulk status result = 0 > usb-storage: Bulk Status S 0x53425355 T 0x3735 R 0 Stat 0x0 > usb-storage: scsi cmd done, result=0x0 > usb-storage: *** thread sleeping. > usb-storage: queuecommand called > usb-storage: *** thread awakened. > usb-storage: Command WRITE_10 (10 bytes) > usb-storage: 2a 00 00 00 00 3f 00 00 08 00 > usb-storage: Bulk Command S 0x43425355 T 0x3736 L 4096 F 0 Trg 0 LUN 0 CL 10 > usb-storage: usb_stor_bulk_transfer_buf: xfer 31 bytes > usb-storage: Status code 0; transferred 31/31 > usb-storage: -- transfer complete > usb-storage: Bulk command transfer result=0 > usb-storage: usb_stor_bulk_transfer_sglist: xfer 4096 bytes, 1 entries > usb-storage: Status code 0; transferred 4096/4096 > usb-storage: -- transfer complete > usb-storage: Bulk data transfer result 0x0 > usb-storage: Attempting to get CSW... > usb-storage: usb_stor_bulk_transfer_buf: xfer 13 bytes > usb-storage: Status code 0; transferred 13/13 > usb-storage: -- transfer complete > usb-storage: Bulk status result = 0 > usb-storage: Bulk Status S 0x53425355 T 0x3736 R 0 Stat 0x0 > usb-storage: scsi cmd done, result=0x0 > usb-storage: *** thread sleeping. That looks perfectly normal. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by: NEC IT Guy Games. Get your fingers limbered up and give it your best shot. 4 great events, 4 opportunities to win big! Highest score wins.NEC IT Guy Games. Play to win an NEC 61 plasma display. Visit http://www.necitguy.com/?r=20 _______________________________________________ Linux-usb-users@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
