| Thomas Maier | 3269485 | 2006-12-08 02:36:12 -0800 | [diff] [blame^] | 1 | What: /sys/class/pktcdvd/ |
| 2 | Date: Oct. 2006 |
| 3 | KernelVersion: 2.6.19 |
| 4 | Contact: Thomas Maier <balagi@justmail.de> |
| 5 | Description: |
| 6 | |
| 7 | sysfs interface |
| 8 | --------------- |
| 9 | |
| 10 | The pktcdvd module (packet writing driver) creates |
| 11 | these files in the sysfs: |
| 12 | (<devid> is in format major:minor ) |
| 13 | |
| 14 | /sys/class/pktcdvd/ |
| 15 | add (0200) Write a block device id (major:minor) |
| 16 | to create a new pktcdvd device and map |
| 17 | it to the block device. |
| 18 | |
| 19 | remove (0200) Write the pktcdvd device id (major:minor) |
| 20 | to it to remove the pktcdvd device. |
| 21 | |
| 22 | device_map (0444) Shows the device mapping in format: |
| 23 | pktcdvd[0-7] <pktdevid> <blkdevid> |
| 24 | |
| 25 | /sys/class/pktcdvd/pktcdvd[0-7]/ |
| 26 | dev (0444) Device id |
| 27 | uevent (0200) To send an uevent. |
| 28 | |
| 29 | /sys/class/pktcdvd/pktcdvd[0-7]/stat/ |
| 30 | packets_started (0444) Number of started packets. |
| 31 | packets_finished (0444) Number of finished packets. |
| 32 | |
| 33 | kb_written (0444) kBytes written. |
| 34 | kb_read (0444) kBytes read. |
| 35 | kb_read_gather (0444) kBytes read to fill write packets. |
| 36 | |
| 37 | reset (0200) Write any value to it to reset |
| 38 | pktcdvd device statistic values, like |
| 39 | bytes read/written. |
| 40 | |
| 41 | /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/ |
| 42 | size (0444) Contains the size of the bio write |
| 43 | queue. |
| 44 | |
| 45 | congestion_off (0644) If bio write queue size is below |
| 46 | this mark, accept new bio requests |
| 47 | from the block layer. |
| 48 | |
| 49 | congestion_on (0644) If bio write queue size is higher |
| 50 | as this mark, do no longer accept |
| 51 | bio write requests from the block |
| 52 | layer and wait till the pktcdvd |
| 53 | device has processed enough bio's |
| 54 | so that bio write queue size is |
| 55 | below congestion off mark. |
| 56 | A value of <= 0 disables congestion |
| 57 | control. |
| 58 | |
| 59 | |
| 60 | Example: |
| 61 | -------- |
| 62 | To use the pktcdvd sysfs interface directly, you can do: |
| 63 | |
| 64 | # create a new pktcdvd device mapped to /dev/hdc |
| 65 | echo "22:0" >/sys/class/pktcdvd/add |
| 66 | cat /sys/class/pktcdvd/device_map |
| 67 | # assuming device pktcdvd0 was created, look at stat's |
| 68 | cat /sys/class/pktcdvd/pktcdvd0/stat/kb_written |
| 69 | # print the device id of the mapped block device |
| 70 | fgrep pktcdvd0 /sys/class/pktcdvd/device_map |
| 71 | # remove device, using pktcdvd0 device id 253:0 |
| 72 | echo "253:0" >/sys/class/pktcdvd/remove |