| What: /sys/class/pktcdvd/ |
| Date: Oct. 2006 |
| KernelVersion: 2.6.20 |
| Contact: Thomas Maier <balagi@justmail.de> |
| Description: |
| |
| sysfs interface |
| --------------- |
| |
| The pktcdvd module (packet writing driver) creates |
| these files in the sysfs: |
| (<devid> is in format major:minor ) |
| |
| /sys/class/pktcdvd/ |
| add (0200) Write a block device id (major:minor) |
| to create a new pktcdvd device and map |
| it to the block device. |
| |
| remove (0200) Write the pktcdvd device id (major:minor) |
| to it to remove the pktcdvd device. |
| |
| device_map (0444) Shows the device mapping in format: |
| pktcdvd[0-7] <pktdevid> <blkdevid> |
| |
| /sys/class/pktcdvd/pktcdvd[0-7]/ |
| dev (0444) Device id |
| uevent (0200) To send an uevent. |
| |
| /sys/class/pktcdvd/pktcdvd[0-7]/stat/ |
| packets_started (0444) Number of started packets. |
| packets_finished (0444) Number of finished packets. |
| |
| kb_written (0444) kBytes written. |
| kb_read (0444) kBytes read. |
| kb_read_gather (0444) kBytes read to fill write packets. |
| |
| reset (0200) Write any value to it to reset |
| pktcdvd device statistic values, like |
| bytes read/written. |
| |
| /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/ |
| size (0444) Contains the size of the bio write |
| queue. |
| |
| congestion_off (0644) If bio write queue size is below |
| this mark, accept new bio requests |
| from the block layer. |
| |
| congestion_on (0644) If bio write queue size is higher |
| as this mark, do no longer accept |
| bio write requests from the block |
| layer and wait till the pktcdvd |
| device has processed enough bio's |
| so that bio write queue size is |
| below congestion off mark. |
| A value of <= 0 disables congestion |
| control. |
| |
| |
| Example: |
| -------- |
| To use the pktcdvd sysfs interface directly, you can do: |
| |
| # create a new pktcdvd device mapped to /dev/hdc |
| echo "22:0" >/sys/class/pktcdvd/add |
| cat /sys/class/pktcdvd/device_map |
| # assuming device pktcdvd0 was created, look at stat's |
| cat /sys/class/pktcdvd/pktcdvd0/stat/kb_written |
| # print the device id of the mapped block device |
| fgrep pktcdvd0 /sys/class/pktcdvd/device_map |
| # remove device, using pktcdvd0 device id 253:0 |
| echo "253:0" >/sys/class/pktcdvd/remove |
