Date: Sat, 17 Dec 2016 12:19:54 +0300 From: Slawa Olhovchenkov <slw@zxy.spb.ru> To: Julian Elischer <julian@freebsd.org> Cc: freebsd-current <freebsd-current@freebsd.org> Subject: Re: FreeBSD system profiling and tuning for 10, 11 and 12 Message-ID: <20161217091954.GE90401@zxy.spb.ru> In-Reply-To: <ccf8774d-21e0-360e-3dee-8f7b5a38f829@freebsd.org> References: <ccf8774d-21e0-360e-3dee-8f7b5a38f829@freebsd.org>
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On Sat, Dec 17, 2016 at 04:06:40PM +0800, Julian Elischer wrote: > Hi > > I'm looking for recent information regarding profiling and tuning in > FreeBSD. > > Google has turned up some links but I think that the best leads are > still hiding.. > for example I only found > https://wiki.freebsd.org/NetworkPerformanceTuning recently. > > (BTW Anyone who has a moment is encouraged to check if they have > anything to add to it.) === Ensure BPF is OFF. No tcpdump, cdpd, lldpd, dhcpd, dhcp-relay. Patches are coming. Check netstat -B. === Don't see any problem with tcpdump up to 40G. tcpdump used for capture selected stream. === On FreeBSD older than 11.0, use more compact ip_fastfoward routine. It processes most packets falling back to 'normal' forward routine for fragments, packets with options, etc. Can save you up to 20% speed (but will break IPSec). net.inet.ip.fastforwarding=1 === I am not found in 11/12 this sysctl/tunable. === Skip feeding /dev/random from network by adding harvest_mask="351" to /etc/rc.conf or theses line to /etc/sysctl.conf: kern.random.sys.harvest.ethernet=0 kern.random.sys.harvest.point_to_point=0 kern.random.sys.harvest.interrupt=0 === On 11: # sysctl kern.random.sys.harvest sysctl: unknown oid 'kern.random.sys.harvest' > I am sure there is better information around for profiling the kernel > and modules, > but I am not seeing "the definitive profiler's guide" out there. I do > know several people > have blogs that cover this sort of thing. If you have one or know of good > profiling resources we should gather them.. send them to me and I'll > try make > sure everything is up to date, and put them together in a wiki page. > > there is already some stuff there, > (see > https://wiki.freebsd.org/NetworkPerformanceTuning?action=fullsearch&context=180&value=profiling&fullsearch=Text > ) > but it could do with gathering together. You might surprised, but various options in BIOS can gain up to 10-20%% every, 50% total. Also, be careful about using internal architectures detials. I am already overloaded: a) bandwidtch of DMI2 link b) bandwidtch of 8x PCIe3 Not all cores equals for IRQ handling and cost of PCIe access.
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