nanog mailing list archives
Re: DPDK and energy efficiency
From: William Herrin <bill () herrin us>
Date: Tue, 23 Feb 2021 14:37:42 -0800
On Tue, Feb 23, 2021 at 2:22 PM Etienne-Victor Depasquale <edepa () ieee org> wrote:
DPDK doesn't inherently do much in the way of power management.I agree - it doesn't. That's not what it was made for.Note that DPDK applications are usually intended to run in very-highdata rate environments where no gains are likely to be realized by avoiding a busy-wait loop. That's not what research shows. Use of LPI states is proposed for power management under high data rate conditions in [5] and in [6], use of the low-power instruction halt is investigated and found to save power under such conditions.
Howdy, This is way too deep in the weeds of developing with the DPDK libraries for your audience here to have much in the way of useful comment. This is an operators group. If anyone is interested, the techniques DPDK offers application authors to manage power on the dataplane cores are described here: https://doc.dpdk.org/guides/prog_guide/power_man.html The main thing devs do, since it's easy, is add a call to rte_pause() in any empty polling loop. IIRC, that just calls the CPU PAUSE instruction which doesn't actually pause anything but saves a little power by de-pipelining and, if hyperthreading is enabled, releasing the core to run the alternate thread. Regards, Bill Herrin -- William Herrin bill () herrin us https://bill.herrin.us/
Current thread:
- Re: DPDK and energy efficiency, (continued)
- Re: DPDK and energy efficiency Etienne-Victor Depasquale (Feb 22)
- Re: DPDK and energy efficiency Robert Bays (Feb 23)
- Re: DPDK and energy efficiency Etienne-Victor Depasquale (Feb 23)
- Re: DPDK and energy efficiency Douglas Fischer (Feb 24)
- Re: DPDK and energy efficiency Robert Bays (Feb 24)
- Re: DPDK and energy efficiency Etienne-Victor Depasquale (Feb 24)
- Re: DPDK and energy efficiency Etienne-Victor Depasquale (Feb 27)
- Re: DPDK and energy efficiency William Herrin (Feb 23)
- Re: DPDK and energy efficiency Etienne-Victor Depasquale (Feb 23)
- Re: DPDK and energy efficiency Etienne-Victor Depasquale (Feb 23)
- Re: DPDK and energy efficiency William Herrin (Feb 23)
- Re: DPDK and energy efficiency Etienne-Victor Depasquale (Feb 23)
- Re: DPDK and energy efficiency Jared Geiger (Feb 22)