2 x quad-core system is slower that 2 x dual core on FreeBSD
rwatson at FreeBSD.org
Tue Dec 4 04:14:26 PST 2007
On Tue, 4 Dec 2007, Krassimir Slavchev wrote:
>>> Evidence in-hand seems to suggest that 8 core systems work very well for
>>> most users, and reflect a significant performance increase with 7.0 over
>>> previous FreeBSD releases.
>> I disagree with that. Heavily loaded Apache, MySQL, Postgres does not work
> There is another report for such problems:
A casual reading suggests that this article is about FreeBSD 6.2, and not
FreeBSD 7.0. Am I misreading?
Robert N M Watson
University of Cambridge
>>>>> The right path forwawrd at this point is to diagnosis the problems
>>>>> and work on fixing them in 8-CURRENT, and assuming they are not
>>>>> highly disruptive, MFC them for FreeBSD 7.1.
>>>> I believe at least the bug with lockmgr contention should be fixed
>>>> before release.
>>> Could you point me at the specific proposed change in question? I
>>> don't think I've seen it come across re@ as a potential merge
>>> request. Changing locking primitives close to a release is, FYI, a
>>> risky business, as while it may improve performance in specific cases,
>>> we may not have a lot of information about more general cases. We
>>> also risk opening up previously nascent race conditions in lock
>> Kris sent me proof of concept patch that helped much against high
>> lockmgr contention. After applying this patch 8-core server become
>> faster that 4-core. But, again, it's still slower than Linux.
>> Here's the patch:
>> Here's Kris saying that it helps:
>> I'm not sure it will help to MySQL and Prostgres, but symptoms are
>> mostly identical.
>> With best regards,
>> Alexey Popov
>> freebsd-stable at freebsd.org mailing list
>> To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.7 (FreeBSD)
> -----END PGP SIGNATURE-----
More information about the freebsd-stable