Date: Sat, 22 Dec 2007 14:07:34 -0500 From: User Ota <ota@animenfo.com> To: Claus Guttesen <kometen@gmail.com> Cc: stable@freebsd.org Subject: Re: SMP on FreeBSD 6.x and 7.0: Worth doing? freenx@deweyonline.com Message-ID: <20071222190734.GA54222@noah.ota.homelinux.net> In-Reply-To: <b41c75520712220440j333286bcs2c497a22880a1d9b@mail.gmail.com> References: <200712220531.WAA09277@lariat.net> <b41c75520712220008v21bc7b47r8376176b54ab8c7e@mail.gmail.com> <20071222090553.GB16381@noah.ota.homelinux.net> <b41c75520712220440j333286bcs2c497a22880a1d9b@mail.gmail.com>
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On Sat, Dec 22, 2007 at 01:40:00PM +0100, Claus Guttesen wrote: > > > > It appears, though I'd need to instrument the code more to be sure, > > > > that the slowdown is coming from file I/O. Could it be that there > > > > less concurrency or more overhead in FreeBSD file operations than > > > > there is in Linux? Even with SoftUpdates turned on, the cache > > > > volume mounted with -noatime, and aufs (which uses kqueues -- a > > > > FreeBSD invention -- to optimize multithreaded disk access), the > > > > benchmark shows FreeBSD losing out. Why? > > > > > > I have noticed an entry in GENERIC called > > > > > > device cpufreq > > > > > > Could this have any influence on the performance (on FreeBSD)? > > > > > > I saw this device late in the 7.0 release-process and I since I'm > > > accustomed to comment out any devices and options I don't need I have > > > commented this out as well. So I haven't performed any tests with and > > > without this device. > > > > > > > Cpufreq is for CPU frequency scaling. In the linux world, the cpufreq > > daemon allows you to control your cpu speed and voltage using power > > profiles and such, which makes it a definite power saving tool for > > laptops. The cpufreq driver is already included with the Linux kernel, > > so I'm going to assume that they've just implemented the cpufreq driver > > in the kernel recently :) > > > > If enabled, it probably would have an impact on performance, however I > > have lost the ability to test such a function since my laptop decides > > not to POST anymore. > > Yes, I did figure out what the purpose of this device was. :-) My > point was that this could lead to lower benchmarks on servers if > GENERIC is used. > > -- > regards > Claus > > When lenity and cruelty play for a kingdom, > the gentlest gamester is the soonest winner. > > Shakespeare > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" Oh, yeah, I see what you mean now. We have GENERIC and SMP kernel configs, with the cpufreq driver now, there should be like a LAPTOP kernel config file with laptop-specific options :P Once I get my laptop working again, though, I'll try testing it out when 7.0-RELEASE comes about. Russell Doucette
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