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DD command using block device as input
Post 302666017 by nytty on Tuesday 3rd of July 2012 02:07:31 PM
07-03-2012
Why is read-ahead a problem since above is only a 512bytes read, all it takes is normally positioning the drive head .. Then if the cache is the reason, it should affect the file as well, but I am getting the same result for all reps?
More importantly, my experiment is really about time/vs blocksize, and I am trying to make it more accurate :
- Shall I only use regular files?
- position the disk head somewhere else after each test?
- is it possible to flush all caches programmatically ?
Sorry for all those questions ..
More importantly, my experiment is really about time/vs blocksize, and I am trying to make it more accurate :
- Shall I only use regular files?
- position the disk head somewhere else after each test?
- is it possible to flush all caches programmatically ?
Sorry for all those questions ..
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LEARN ABOUT DEBIAN
smfplay
SMFPLAY(1) BSD General Commands Manual SMFPLAY(1) NAME
smfplay -- play a standard MIDI file SYNOPSIS
smfplay [-mxy] [-g measure] [-d devname] [-i devname] midifile DESCRIPTION
The smfplay utility plays a MIDI file. While playing, it can route events from one midi(4) device to another. To stop performance, send an interrupt signal to smfplay (for instance by pressing control ^C on the terminal). The options are as follows: -m Use metronome. The metronome will follow tempo changes and time signature changes in the midi file. -x Synchronise to an external midi(4) device. If the -i flag is used then playback will be synchronised to the input device else it will be synchronised to the default device. -y Send midi timing information to the default device. Useful if the output device is a slave MIDI sequencer. -g measure Start playback at the given measure number. -d filename Default midi(4) device on which to play the midi file. If not specified, the content of the MIDIDEV environment variable will be used instead. -i filename Alternate input midi(4) device. Voice events (notes, controllers, etc) received on the input device will be sent as-is to the default device. Without this flag, the default device will be used for input. The smfplay utility is an interface to midish(1). If more specific features are needed, the user may consider using midish(1). EXAMPLES
The following will play mysong.mid on device /dev/rmidi4 and will use metronome. $ smfplay -m -d /dev/rmidi4 mysong.mid SEE ALSO
smfrec(1), midish(1), midiplay(1), midi(4) BSD
August 22, 2005 BSD