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Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-pktcdvd')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-pktcdvd | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-pktcdvd b/Documentation/ABI/testing/sysfs-class-pktcdvd new file mode 100644 index 000000000000..c4c55edc9a5c --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-pktcdvd @@ -0,0 +1,72 @@ +What: /sys/class/pktcdvd/ +Date: Oct. 2006 +KernelVersion: 2.6.19 +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 |