Hi, On Wed, 8 Oct 2014 16:55:38 -0700 Paul Von-Stamwitz <PVonStamwitz@xxxxxxxxxxxxxx> wrote: > > > > Hi, > > > > > > as mentioned during today's meeting, here are the kernel boot > > > parameters > > which I found to provide the basis for good performance results: > > > > > > processor.max_cstate=0 > > > intel_idle.max_cstate=0 > > > > > > I understand these to basically turn off any power saving modes > > > of the > > CPU; the CPU's we are using are like > > > Intel(R) Xeon(R) CPU E5-2640 v2 @ 2.00GHz > > > Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz > > > > > > At the BIOS level, we > > > - turn off Hyperthraeding > > > - turn off Turbo mode (in order ot not leave the specifications) > > > - turn on frequency floor override > > > > > > We also assert that > > > /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor > > > is set to "performance" > > > > > > Using above we see a constant frequency at the maximum level > > > allowed by > > the CPU (except Turbo mode). > > > > How much performance do we gain by this? Till now i thought it's > > just 1-3% so i'm still running ondemand govenor plus power savings. > > As always, it depends. I saw noticeable increases in some throughput > tests (though I can't recall the % gain.) More important to me was > that it made my fio results much more consistent. As we measure > improvements, these settings remove some of the "system noise". > > Best, > Paul > There were two different aspects which showed improvemnt: - code was executed faster - thread switching delays were reduced significantly See the attached grahics. They show processing of a 4 kB write request: processing at the Pipe::Reader is roughly 200 us in both pictures, and sth. like 20 us at the OSD::Dispatcher. So there is not much of a benefit here. But the delay between the end of the Pipe::Reader and the start of the OSD::Dispatcher threads reduced really significantly. (And sorry for the late response) > > > > Greets, > > Stefan > > > > > Best Regards > > > > > > Andreas Bluemle > > > > > > > > > > > > > > > > > > > > > On Wed, 8 Oct 2014 02:51:21 +0200 > > > Mark Nelson <mark.nelson@xxxxxxxxxxx> wrote: > > > > > >> Hi All, > > >> > > >> Just a remind that the weekly performance meeting is on > > >> Wednesdays at 8AM PST. Same bat time, same bat channel! > > >> > > >> Etherpad URL: > > >> http://pad.ceph.com/p/performance_weekly > > >> > > >> To join the Meeting: > > >> https://bluejeans.com/268261044 > > >> > > >> To join via Browser: > > >> https://bluejeans.com/268261044/browser > > >> > > >> To join with Lync: > > >> https://bluejeans.com/268261044/lync > > >> > > >> > > >> To join via Room System: > > >> Video Conferencing System: bjn.vc -or- 199.48.152.152 Meeting ID: > > >> 268261044 > > >> > > >> To join via Phone: > > >> 1) Dial: > > >> +1 408 740 7256 > > >> +1 888 240 2560(US Toll Free) > > >> +1 408 317 9253(Alternate Number) > > >> (see all numbers - http://bluejeans.com/numbers) > > >> 2) Enter Conference ID: 268261044 > > >> > > >> Mark > > >> -- > > >> To unsubscribe from this list: send the line "unsubscribe > > >> ceph-devel" in the body of a message to > > >> majordomo@xxxxxxxxxxxxxxx More > > majordomo > > >> info at http://vger.kernel.org/majordomo-info.html > > >> > > >> > > > > > > > > > > > > -- > > > Andreas Bluemle > > > mailto:Andreas.Bluemle@xxxxxxxxxxx ITXperts > > > GmbH http://www.itxperts.de Balanstrasse > > > 73, Geb. 08 Phone: (+49) 89 89044917 D-81541 Muenchen > > > (Germany) Fax: (+49) 89 89044910 > > > > > > Company details: http://www.itxperts.de/imprint.htm > > > -- > > > To unsubscribe from this list: send the line "unsubscribe > > > ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More > > majordomo > > > info at http://vger.kernel.org/majordomo-info.html > > > > > > ________________________________ > > > > > > PLEASE NOTE: The information contained in this electronic mail > > > message is > > intended only for the use of the designated recipient(s) named > > above. 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If you have received this > > communication in error, please notify the sender by telephone or > > e-mail (as shown above) immediately and destroy any and all copies > > of this message in your possession (whether hard copies or > > electronically stored copies). > > > > > > -- > > > To unsubscribe from this list: send the line "unsubscribe > > > ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More > > majordomo > > > info at http://vger.kernel.org/majordomo-info.html > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe > > ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- Andreas Bluemle mailto:Andreas.Bluemle@xxxxxxxxxxx ITXperts GmbH http://www.itxperts.de Balanstrasse 73, Geb. 08 Phone: (+49) 89 89044917 D-81541 Muenchen (Germany) Fax: (+49) 89 89044910 Company details: http://www.itxperts.de/imprint.htm
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