Date: Mon, 19 Nov 2007 14:02:25 +0000 (GMT) From: Robert Watson <rwatson@FreeBSD.org> To: Alexey Popov <lol@chistydom.ru> Cc: freebsd-stable@freebsd.org Subject: Re: 2 x quad-core system is slower that 2 x dual core on FreeBSD Message-ID: <20071119140019.V80667@fledge.watson.org> In-Reply-To: <4741905E.8050300@chistydom.ru> References: <4741905E.8050300@chistydom.ru>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 19 Nov 2007, Alexey Popov wrote: > I tried Linux and it works much better than old (2 x dual-core) backends. It > handles 2 times more requests than FreeBSD on the old backends. So there's a > real scalability problem in FreeBSD. The more processors it have the more > CPU time it consumes. > > Also I faced the same problem moving heavily loaded MySQL-server to new > hardware. That time I thought that the problem is in the mysql-server itself > and I had to install Linux. > > See in attach: mutex statistics for quad-core system and dmesg and vmstat > for dual- and quad-core systems. > > What can I do to make FreeBSD run faster on many-CPU systems??? Have you configured libmap.conf to force MySQL to use libthr instead of libpthread? libpthread is known to have serious performance bottlenecks for MySQL as compared to libthr. FreeBSD 7 contains significant optimization for increased numbers of cores, and is where a lot of the work optimizing MySQL has ended up. I see you're trying out a 6.3 beta, any chance you could try out a 7.0 beta instead? Also, consider switching to "options SCHED_ULE" in the 7.0 kernel rather than "options SCHED_4BSD". Robert N M Watson Computer Laboratory University of Cambridge
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20071119140019.V80667>