* Re: [gentoo-user] kernel tuning
@ 2005-10-03 20:51 99% ` Brett I. Holcomb
0 siblings, 0 replies; 1+ results
From: Brett I. Holcomb @ 2005-10-03 20:51 UTC (permalink / raw
To: gentoo-user
Thank you for the explanation. I missed that servers is what the OP is
really interested in. I'll look at the scheduler options again.
On Mon, 3 Oct 2005, Bastian Balthazar Bux wrote:
> Brett I. Holcomb wrote:
>> Out of curiosity and so I can learn. Why did you suggest CONFIG_HZ be
>> set to 100 (IIRC default is 250) and also what exactly is it supposed to
>> do for you. We did not have it before.
>>
>
> In the past was fixed to 100Hz, then to 1000 appeared, now there is a
> third option for 250, the current default and a good compromise.
>
> An home system become more responsive with a higher frequency.
>
> cpu and interrupt timings become lower with a lower frequency, so it's
> better for a server system. Expecially a multi processor one.
>
>
>
>> Also what about CONFIG_PREMPT being none? The help mentions it is for
>> low latency.
>
>>> CONFIG_HZ=100
>>> CONFIG_PREEMPT_NONE=y
>>> IOSCHED_AS || IOSCHED_DEADLINE || IOSCHED_CFQ
>>>
>
> Preemption permit to interrupt kernel processes, providing a still more
> responsive kernel. Good if you're hering music, playing videos and such
> but not very interesting for a server.
>
> The third option is the "scheduler" (IOSCHED_*) how the kernel access
> the disk. this has been discussed in great detail over the net.
> Quoting the kernel help here, since it's short and explanatory.
>
> --------- quote ---------
> CONFIG_IOSCHED_AS:
>
> The anticipatory I/O scheduler is the default disk scheduler. It is
> generally a good choice for most environments, but is quite large and
> complex when compared to the deadline I/O scheduler, it can also be
> slower in some cases especially some database loads.
>
> Symbol: IOSCHED_AS [=y]
> Prompt: Anticipatory I/O scheduler
> Defined at drivers/block/Kconfig.iosched:14
> Location:
> -> Device Drivers
> -> Block devices
> -> IO Schedulers
> --------- quote ---------
>
>
--
Brett I. Holcomb
brettholcomb@R777bellsouth.net
Registered Linux User #188143
Remove R777 to email
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2005-10-01 16:11 [gentoo-user] kernel tuning John Jolet
2005-10-01 17:49 ` Mark Shields
2005-10-01 19:59 ` gentuxx
2005-10-02 22:33 ` John Jolet
2005-10-03 19:09 ` Bastian Balthazar Bux
2005-10-03 19:19 ` Brett I. Holcomb
2005-10-03 20:46 ` Bastian Balthazar Bux
2005-10-03 20:51 99% ` Brett I. Holcomb
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