HZ in RELENG_5? tcp_subr.c related

[Ronald Klop]

Just put something like this in /boot/loader.conf.

kern.hz="250"

It works for me since a long time (freebsd 4 I think).

Ronald.

On Tue, 22 Feb 2005 12:52:06 -0800, Kevin Oberman <oberman at es.net> wrote:

>> Date: Tue, 22 Feb 2005 19:56:03 +0000 (GMT)
>> From: Robert Watson <rwatson at FreeBSD.org>
>>
>>
>> On Tue, 22 Feb 2005, Kevin Oberman wrote:
>>
>> > > In RELENG_5, the default HZ for amd64 is 1000, but for all other  
>> platforms
>> > > it is 100.  So amd64 users will see a ten-fold decrease in  
>> tcp_isn_tick()
>> > > running, but i386 (and other) users will see no change.
>> >
>> > Now that 5 is STABLE, I guess we are stuck with it, but in an era of
>> > "slow" 2GHz systems, it seems like a questionable choice. I know that
>> > there are a lot of folks running old hardware (like my trusty old K6),
>> > but they are a minority and changing HZ is not a big deal. Why make  
>> the
>> > majority live with 100 on fast systems or know enough to manually  
>> change
>> > it?
>> >
>> > Has there been discussion of changing this for V6 or is there a  
>> reason I
>> > missed for keeping HZ at 100 in the iX86 platforms.
>>
>> In 6-CURRENT, HZ is 1000 for amd64, i386, and ia64, but 100 for other
>> platforms (i.e., ppc, arm, and alpha).  I'm not opposed to merging the  
>> HZ
>> change to RELENG_5 at some point, but given that occasional nits, such  
>> as
>> the TCP nit, are turning up, I think it's worth waiting until after 5.4.
>
> Let's keep STABLE stable. If there are timing issues with HZ of 1000 in
> V5, we clearly would not want to change before they are resolved.
> Happily, I have not see these on my faster systems and have not
> increased HZ on anything < 1 GHz.
>
> If I do see network problems, now I know another place to look, too.
>
> Thanks!



-- 
  Ronald Klop
  Amsterdam, The Netherlands