disk I/O, VFS hirunningspace

[Attilio Rao]

2010/7/15 Alan Cox <alan.l.cox at gmail.com>:
> On Thu, Jul 15, 2010 at 8:01 AM, Ivan Voras <ivoras at freebsd.org> wrote:
>
>> On 07/14/10 18:27, Jerry Toung wrote:
>> > On Wed, Jul 14, 2010 at 12:04 AM, Gary Jennejohn
>> > <gljennjohn at googlemail.com>wrote:
>> >
>> >>
>> >>
>> >> Rather than commenting out the code try setting the sysctl
>> >> vfs.hirunningspace to various powers-of-two.  Default seems to be
>> >> 1MB.  I just changed it on the command line as a test to 2MB.
>> >>
>> >> You can do this in /etc/sysctl.conf.
>> >>
>> >>
>> > thank you all, that did it. The settings that Matt recommended are giving
>> > the same numbers
>>
>> Any objections to raising the defaults to 8 MB / 1 MB in HEAD?
>>
>>
>>
> Keep in mind that we still run on some fairly small systems with limited I/O
> capabilities, e.g., a typical arm platform.  More generally, with the range
> of systems that FreeBSD runs on today, any particular choice of constants is
> going to perform poorly for someone.  If nothing else, making these sysctls
> a function of the buffer cache size is probably better than any particular
> constants.

What about making a MD sysctl?

Attilio


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