2006-12-08 18:36:12 +08:00
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What: /sys/class/pktcdvd/
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Date: Oct. 2006
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2007-02-10 17:45:11 +08:00
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KernelVersion: 2.6.20
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2006-12-08 18:36:12 +08:00
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Contact: Thomas Maier <balagi@justmail.de>
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Description:
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sysfs interface
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---------------
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The pktcdvd module (packet writing driver) creates
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these files in the sysfs:
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(<devid> is in format major:minor )
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/sys/class/pktcdvd/
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add (0200) Write a block device id (major:minor)
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to create a new pktcdvd device and map
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it to the block device.
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remove (0200) Write the pktcdvd device id (major:minor)
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to it to remove the pktcdvd device.
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device_map (0444) Shows the device mapping in format:
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pktcdvd[0-7] <pktdevid> <blkdevid>
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/sys/class/pktcdvd/pktcdvd[0-7]/
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dev (0444) Device id
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uevent (0200) To send an uevent.
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/sys/class/pktcdvd/pktcdvd[0-7]/stat/
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packets_started (0444) Number of started packets.
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packets_finished (0444) Number of finished packets.
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kb_written (0444) kBytes written.
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kb_read (0444) kBytes read.
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kb_read_gather (0444) kBytes read to fill write packets.
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reset (0200) 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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/sys/class/pktcdvd/pktcdvd[0-7]/write_queue/
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size (0444) Contains the size of the bio write
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queue.
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congestion_off (0644) If bio write queue size is below
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this mark, accept new bio requests
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from the block layer.
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congestion_on (0644) If bio write queue size is higher
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as this mark, do no longer accept
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bio write requests from the block
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layer and wait till the pktcdvd
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device has processed enough bio's
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so that bio write queue size is
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below congestion off mark.
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A value of <= 0 disables congestion
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control.
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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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