Subject: Re: HEADS UP: gdamore-uart branch
To: Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>
From: Garrett D'Amore <garrett_damore@tadpole.com>
List: tech-kern
Date: 07/11/2006 12:47:21
These numbers are quite useful.  Thanks.  What it really shows is that
COM_REGMAP does make a tiny difference (as expected), and apparently the
default non-COM_REGMAP case runs as well as stock.  (The difference is
so small that it appears to be in the noise.)

Even the COM_REGMAP case is pretty darn good.  Good enough that I wonder
if it is worth simplifying and cleaning the code by making COM_REGMAP
the default (and only) case.  I.e. I wonder if it really buys enough to
be worth _not_ defining it.

I won't commit it that way, but if someone wants to make that the case,
or if the consensus is that it should be so, then I will make whatever
appropriate change is needed after merging gdamore-uart into HEAD.

    -- Garrett

Izumi Tsutsui wrote:
>> Maybe I should check which part causes such difference,
>> but I haven't checked any compiled code yet.
>>     
>
> With ttcp(1) from pkgsrc on hp425t, there is few visible difference:
>
> at peer (1.3GHz PC):
> ---
> # ifconfig sl0 create
> # slattach -h -s 38400 /dev/tty00
> # ifconfig sl0 192.168.100.1 192.168.100.2
>  :
> # ttcp -ts -l 8192 -n 16 192.168.100.2
> ---
>
> sl0 settings on hp425t:
> ---
> # ifconfig sl0 create
> # slattach -h -s 38400 /dev/ttyC0
> # ifconfig sl0 192.168.100.2 192.168.100.1
> ---
>
> HEAD GENERIC:
> ---
> # ttcp -rs -l 8192 -n 16
> ttcp-r: buflen=8192, nbuf=16, align=16384/0, port=5001  tcp
> ttcp-r: socket
> ttcp-r: accept from 192.168.100.1
> ttcp-r: 131072 bytes in 41.76 real seconds = 3.06 KB/sec +++
> ttcp-r: 535 I/O calls, msec/call = 79.94, calls/sec = 12.81
> ttcp-r: 0.0user 0.3sys 0:41real 0% 0i+0d 0maxrss 0+1pf 534+5csw
> ---
>
> gdamore-uart GENERIC:
> ---
> # ttcp -rs -l 8192 -n 16
> ttcp-r: buflen=8192, nbuf=16, align=16384/0, port=5001  tcp
> ttcp-r: socket
> ttcp-r: accept from 192.168.100.1
> ttcp-r: 131072 bytes in 41.75 real seconds = 3.07 KB/sec +++
> ttcp-r: 539 I/O calls, msec/call = 79.32, calls/sec = 12.91
> ttcp-r: 0.0user 0.2sys 0:41real 0% 0i+0d 0maxrss 0+1pf 538+4csw
> ---
>
> gdamore-uart GENERIC + COM_REGMAP:
> ---
> # ttcp -rs -l 8192 -n 16
> ttcp-r: buflen=8192, nbuf=16, align=16384/0, port=5001  tcp
> ttcp-r: socket
> ttcp-r: accept from 192.168.100.1
> ttcp-r: 131072 bytes in 41.81 real seconds = 3.06 KB/sec +++
> ttcp-r: 509 I/O calls, msec/call = 84.12, calls/sec = 12.17
> ttcp-r: -1.9user 0.3sys 0:41real 0% 0i+0d 0maxrss 6+3pf 515+14csw
> ---
>
> (Heh, 0.01 real second could cause difference of 0.01KB/sec)
> ---
> Izumi Tsutsui
>   


-- 
Garrett D'Amore, Principal Software Engineer
Tadpole Computer / Computing Technologies Division,
General Dynamics C4 Systems
http://www.tadpolecomputer.com/
Phone: 951 325-2134  Fax: 951 325-2191