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