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3 commits

Author SHA1 Message Date
Stephen Hemminger
9eb2d62719 [TCP] cubic: use Newton-Raphson
Replace cube root algorithim with a faster version using Newton-Raphson.
Surprisingly, doing the scaled div64_64 is faster than a true 64 bit
division on 64 bit CPU's.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:11:09 -08:00
Stephen Hemminger
89b3d9aaf4 [TCP] cubic: precompute constants
Revised version of patch to pre-compute values for TCP cubic.
  * d32,d64 replaced with descriptive names
  * cube_factor replaces
	 srtt[scaled by count] / HZ * ((1 << (10+2*BICTCP_HZ)) / bic_scale)
  * beta_scale replaces
	8*(BICTCP_BETA_SCALE+beta)/3/(BICTCP_BETA_SCALE-beta);

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:11:08 -08:00
Stephen Hemminger
df3271f336 [TCP] BIC: CUBIC window growth (2.0)
Replace existing BIC version 1.1 with new version 2.0.
The main change is to replace the window growth function
with a cubic function as described in:
  http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:10:28 -08:00