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Commit | Line | Data |
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32694850 TM |
1 | What: /sys/class/pktcdvd/ |
2 | Date: Oct. 2006 | |
83f3aa3d | 3 | KernelVersion: 2.6.20 |
32694850 TM |
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 |