So, I'm using dd to write the Gentoo LiveDVD ISO directly to an SDHC card. I was wondering why the transfer rate had slowed from 20MB/s to 6MB/s, so I ran 'sudo tail -f /var/log/messages' to see if there were I/O errors slowing things down.
What I found was a flood-stream of message blocks that look like this: Jun 17 19:21:18 saffron kernel: [39023.458632] usb-storage: queuecommand_lck called Jun 17 19:21:18 saffron kernel: [39023.458670] usb-storage: *** thread awakened. Jun 17 19:21:18 saffron kernel: [39023.458685] usb-storage: Command WRITE_10 (10 bytes) Jun 17 19:21:18 saffron kernel: [39023.458687] usb-storage: 2a 00 00 2b f3 80 00 00 f0 00 Jun 17 19:21:18 saffron kernel: [39023.458694] usb-storage: rts51x_invoke_transport: <--- Jun 17 19:21:18 saffron kernel: [39023.458697] usb-storage: rts51x_invoke_transport: working scsi, intf->pm_usage_cnt:1,power.usage:1 Jun 17 19:21:18 saffron kernel: [39023.458701] usb-storage: Bulk Command S 0x43425355 T 0x34ef L 122880 F 0 Trg 0 LUN 0 CL 10 Jun 17 19:21:18 saffron kernel: [39023.458704] usb-storage: usb_stor_bulk_transfer_buf: xfer 31 bytes Jun 17 19:21:18 saffron kernel: [39023.458759] usb-storage: Status code 0; transferred 31/31 Jun 17 19:21:18 saffron kernel: [39023.458761] usb-storage: -- transfer complete Jun 17 19:21:18 saffron kernel: [39023.458763] usb-storage: Bulk command transfer result=0 Jun 17 19:21:18 saffron kernel: [39023.458766] usb-storage: usb_stor_bulk_transfer_sglist: xfer 122880 bytes, 18 entries Jun 17 19:21:18 saffron kernel: [39023.486031] usb-storage: Status code 0; transferred 122880/122880 Jun 17 19:21:18 saffron kernel: [39023.486035] usb-storage: -- transfer complete Jun 17 19:21:18 saffron kernel: [39023.486037] usb-storage: Bulk data transfer result 0x0 Jun 17 19:21:18 saffron kernel: [39023.486039] usb-storage: Attempting to get CSW... Jun 17 19:21:18 saffron kernel: [39023.486042] usb-storage: usb_stor_bulk_transfer_buf: xfer 13 bytes Jun 17 19:21:18 saffron kernel: [39023.491787] usb-storage: Status code 0; transferred 13/13 Jun 17 19:21:18 saffron kernel: [39023.491790] usb-storage: -- transfer complete Jun 17 19:21:18 saffron kernel: [39023.491793] usb-storage: Bulk status result = 0 Jun 17 19:21:18 saffron kernel: [39023.491795] usb-storage: Bulk Status S 0x53425355 T 0x34ef R 0 Stat 0x0 Jun 17 19:21:18 saffron kernel: [39023.491800] usb-storage: rts51x_invoke_transport: state:2 Jun 17 19:21:18 saffron kernel: [39023.491802] usb-storage: rts51x_modi_suspend_timer: <---, state:2 Jun 17 19:21:18 saffron kernel: [39023.491805] usb-storage: rts51x_modi_suspend_timer: ---> Jun 17 19:21:18 saffron kernel: [39023.491807] usb-storage: rts51x_invoke_transport: ---> Jun 17 19:21:18 saffron kernel: [39023.491809] usb-storage: scsi cmd done, result=0x0 Jun 17 19:21:18 saffron kernel: [39023.491815] usb-storage: *** thread sleeping. ... Any idea what kernel configuration flag I may have enabled to cause these to be continually generated? My first guess would be something like 'kernel lock debugging'...if that's what I'm seeing here, where would I go to file a bug report against the usb-storage subsystem? -- :wq
