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A double is 8 bytes, and each character in a text-based output is probably >= 1 byte, depending on the encoding. If the double value actually holds less than 8 characters, I am surprised that a float value does not suffice. What other info does the database include that is increasing its size? - Nilay Vaish On Jan. 15, 2013, 10:36 a.m., Andreas Hansson wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > http://reviews.gem5.org/r/1646/ > ----------------------------------------------------------- > > (Updated Jan. 15, 2013, 10:36 a.m.) > > > Review request for Default. > > > Description > ------- > > Changeset 9499:bc23f2c316fc > --------------------------- > stats: Store vector stats using doubles and compress with zlib > > This patch changes any arrays of values to be stored as an array of doubles, > rather than floats in the SQL database. This is required as floats lose too > much > accuracy. For example, if the stats are read from the database, and injected > back into gem5's stats system, then formulas can be recalculated. If floats > are > used, these formulas evaluate to be different from those originally calculated > when creating the SQL database. > > As doubles take up twice the space of a float (8 Bytes vs 4 Bytes) the SQL > database becomes larger. The end result is that the database is larger than > the > text based output without compression. Therefore, as the vector storage is > already not human readable we compress this field using zlib. zlib has been in > the python standard library since version 1.5.1. so it is already covered in > the gem5 build prerequisites. > > > Diffs > ----- > > src/python/m5/stats/sql.py PRE-CREATION > > Diff: http://reviews.gem5.org/r/1646/diff/ > > > Testing > ------- > > > Thanks, > > Andreas Hansson > > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
