|
| 1 | +sysfs interface |
| 2 | +--------------- |
| 3 | +The pktcdvd module (packet writing driver) creates the following files in the |
| 4 | +sysfs: (<devid> is in the format major:minor) |
| 5 | + |
| 6 | +What: /sys/class/pktcdvd/add |
| 7 | +What: /sys/class/pktcdvd/remove |
| 8 | +What: /sys/class/pktcdvd/device_map |
| 9 | +Date: Oct. 2006 |
| 10 | +KernelVersion: 2.6.20 |
| 11 | +Contact: Thomas Maier <balagi@justmail.de> |
| 12 | +Description: |
| 13 | + |
| 14 | + ========== ============================================== |
| 15 | + add (WO) Write a block device id (major:minor) to |
| 16 | + create a new pktcdvd device and map it to the |
| 17 | + block device. |
| 18 | + |
| 19 | + remove (WO) Write the pktcdvd device id (major:minor) |
| 20 | + to remove the pktcdvd device. |
| 21 | + |
| 22 | + device_map (RO) Shows the device mapping in format: |
| 23 | + pktcdvd[0-7] <pktdevid> <blkdevid> |
| 24 | + ========== ============================================== |
| 25 | + |
| 26 | + |
| 27 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/dev |
| 28 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/uevent |
| 29 | +Date: Oct. 2006 |
| 30 | +KernelVersion: 2.6.20 |
| 31 | +Contact: Thomas Maier <balagi@justmail.de> |
| 32 | +Description: |
| 33 | + dev: (RO) Device id |
| 34 | + |
| 35 | + uevent: (WO) To send a uevent |
| 36 | + |
| 37 | + |
| 38 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/packets_started |
| 39 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/packets_finished |
| 40 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_written |
| 41 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_read |
| 42 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/kb_read_gather |
| 43 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/stat/reset |
| 44 | +Date: Oct. 2006 |
| 45 | +KernelVersion: 2.6.20 |
| 46 | +Contact: Thomas Maier <balagi@justmail.de> |
| 47 | +Description: |
| 48 | + packets_started: (RO) Number of started packets. |
| 49 | + |
| 50 | + packets_finished: (RO) Number of finished packets. |
| 51 | + |
| 52 | + kb_written: (RO) kBytes written. |
| 53 | + |
| 54 | + kb_read: (RO) kBytes read. |
| 55 | + |
| 56 | + kb_read_gather: (RO) kBytes read to fill write packets. |
| 57 | + |
| 58 | + reset: (WO) Write any value to it to reset |
| 59 | + pktcdvd device statistic values, like |
| 60 | + bytes read/written. |
| 61 | + |
| 62 | + |
| 63 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/size |
| 64 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/congestion_off |
| 65 | +What: /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/congestion_on |
| 66 | +Date: Oct. 2006 |
| 67 | +KernelVersion: 2.6.20 |
| 68 | +Contact: Thomas Maier <balagi@justmail.de> |
| 69 | +Description: |
| 70 | + ============== ================================================ |
| 71 | + size (RO) Contains the size of the bio write queue. |
| 72 | + |
| 73 | + congestion_off (RW) If bio write queue size is below this mark, |
| 74 | + accept new bio requests from the block layer. |
| 75 | + |
| 76 | + congestion_on (RW) If bio write queue size is higher as this |
| 77 | + mark, do no longer accept bio write requests |
| 78 | + from the block layer and wait till the pktcdvd |
| 79 | + device has processed enough bio's so that bio |
| 80 | + write queue size is below congestion off mark. |
| 81 | + A value of <= 0 disables congestion control. |
| 82 | + ============== ================================================ |
| 83 | + |
| 84 | + |
| 85 | +Example: |
| 86 | +-------- |
| 87 | +To use the pktcdvd sysfs interface directly, you can do:: |
| 88 | + |
| 89 | + # create a new pktcdvd device mapped to /dev/hdc |
| 90 | + echo "22:0" >/sys/class/pktcdvd/add |
| 91 | + cat /sys/class/pktcdvd/device_map |
| 92 | + # assuming device pktcdvd0 was created, look at stat's |
| 93 | + cat /sys/class/pktcdvd/pktcdvd0/stat/kb_written |
| 94 | + # print the device id of the mapped block device |
| 95 | + fgrep pktcdvd0 /sys/class/pktcdvd/device_map |
| 96 | + # remove device, using pktcdvd0 device id 253:0 |
| 97 | + echo "253:0" >/sys/class/pktcdvd/remove |
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