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jkorell / iperf

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flush file with writing with -F flag #113

Closed GoogleCodeExporter closed 8 years ago

GoogleCodeExporter commented 8 years ago 

Disk write performance will be more accurate if iperf3 uses fflush() after each 
block to eliminate disk cache effects.

Original issue reported on code.google.com by bltier...@es.net on 25 Nov 2013 at 5:39

GoogleCodeExporter commented 8 years ago

Original comment by bltier...@es.net on 25 Nov 2013 at 5:39

GoogleCodeExporter commented 8 years ago 
fflush() is for stdio and the -F stuff does not use stdio, it's doing 
read()/write(). So this particular cache effect does not apply. There are of 
course other caches in the pipeline.

Original comment by jef.posk...@gmail.com on 25 Nov 2013 at 5:50

GoogleCodeExporter commented 8 years ago 
Maybe fsync() is what we want?  I'll give that a try.

Original comment by jef.posk...@gmail.com on 25 Nov 2013 at 5:53

GoogleCodeExporter commented 8 years ago 
I think I meant 'fsync':

http://linux.die.net/man/2/fsync

Original comment by bltier...@es.net on 25 Nov 2013 at 5:55

GoogleCodeExporter commented 8 years ago

Original comment by jef.posk...@gmail.com on 25 Nov 2013 at 5:59