svn commit: r202894 - in head/sys/i386: i386 include

[Alexander Leidinger]

Quoting John Baldwin <jhb at freebsd.org> (from Tue, 26 Jan 2010 15:07:21 -0500):

> On Tuesday 26 January 2010 12:05:29 pm Ivan Voras wrote:
>> 2010/1/26 Alexander Leidinger <Alexander at leidinger.net>:
>> >
>> > Quoting John Baldwin <jhb at freebsd.org> (from Mon, 25 Jan 2010 07:57:49
>> > -0500):
>> >
>> >> On Saturday 23 January 2010 1:42:28 pm Alan Cox wrote:
>> >>>
>> >>> Author: alc
>> >>> Date: Sat Jan 23 18:42:28 2010
>> >>> New Revision: 202894
>> >>> URL: http://svn.freebsd.org/changeset/base/202894
>> >>>
>> >>> Log:
>> >>>  Handle a race between pmap_kextract() and pmap_promote_pde().   
>> This race
>> >>> is
>> >>>  known to cause a kernel crash in ZFS on i386 when superpage  
>> promotion is
>> >>>  enabled.
>> >>>
>> >>>  Tested by:    netchild
>> >>>  MFC after:    1 week
>> >>
>> >> Yay!  Should we enable pg_ps by default on i386 now?
>> >
>> > Data point, the i386 system where I have superpages enabled is a p4 with
>> > currently 11 jails active. Some webservers, squid, samba, bind,  
>> postfix and
>> > a lot of portupgrades (during the last days, I'm updating a jail with a
>> > desktop-setup inside). All jails are on ZFS.
>>
>> Do you have any method of comparing performance before-and-after?
>> There was a thread on some of the mailing lists (stable@/current@?)
>> about squid being the pessimal case for superpages.
>
> The thread did not say that superpages made squid slower, rather that due to
> the way it forked to execute the log rotation binaries, some superpages were
> demoted back to regular pages losing the gain of superpages for those pages.

Additionally:
  - this is my server at home (limited amount of users accessing it)
  - I changed too much at once which may affect the performance
    (superpages, ATA_CAM, zfs-kernel-settings)

Apart from that: I have no performance numbers for this machine.

Bye,
Alexander.

-- 
Fresco's Discovery:
	If you knew what you were doing you'd probably be bored.

http://www.Leidinger.net    Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org       netchild @ FreeBSD.org  : PGP ID = 72077137