Date: Thu, 23 Feb 2012 08:22:16 -0500 From: John Baldwin <jhb@freebsd.org> To: freebsd-hackers@freebsd.org Cc: "hackers@freebsd.org" <hackers@freebsd.org>, Doug Barton <dougb@freebsd.org>, Ivan Voras <ivoras@freebsd.org> Subject: Re: PostgreSQL benchmarks (now with Linux numbers) Message-ID: <201202230822.16304.jhb@freebsd.org> In-Reply-To: <4F45AB76.5050201@FreeBSD.org> References: <b1732c99-eec2-4097-ad9c-f58979addf9f@email.android.com> <4F45AB76.5050201@FreeBSD.org>
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On Wednesday, February 22, 2012 9:59:02 pm Doug Barton wrote: > On 02/22/2012 01:42, Ivan Voras wrote: > > The Dragonfly team has recently liberated their VM from the giant lock and there are some interesting benchmarks comparing it to FreeBSD 9 and a derivative of RedHat Enterprise Linux: > > > > http://leaf.dragonflybsd.org/mailarchive/kernel/2011-11/msg00008.html > > > > Other developments are described in their release notes: http://www.dragonflybsd.org/release30/ > > The 4.5 times improvement by enabling kern.ipc.shm_use_phys is pretty > notable, what prevents us from enabling that by default? It makes all your SYSV SHMs wired. That's fine if you are running a dedicated server using SYSV SHMs where you want that process to use all the RAM in the machine (e.g. a pgqsl server). It's not so great for a general purpose load where you would like an otherwise-idle process using SYSV SHMs to have the SHMs paged out to swap if other processes on the machine need memory and the box is under memory pressure. -- John Baldwin
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