From: Thomas Monjalon <thomas@monjalon.net>
To: "Hunt, David" <david.hunt@intel.com>
Cc: dev@dpdk.org, jerin.jacob@caviumnetworks.com,
hemant.agrawal@nxp.com, arybchenko@solarflare.com,
ferruh.yigit@intel.com, bruce.richardson@intel.com
Subject: Re: [dpdk-dev] [0/9] examples/vm_power: 100% Busy Polling
Date: Wed, 18 Jul 2018 17:23:04 +0200 [thread overview]
Message-ID: <2801427.dF8lWImUGl@xps> (raw)
In-Reply-To: <bad9d95b-52b6-ebc2-4ac0-498d299910ef@intel.com>
13/07/2018 10:43, Hunt, David:
>
> On 13/7/2018 9:33 AM, Thomas Monjalon wrote:
> > 13/07/2018 10:31, Hunt, David:
> >> Hi Thomas,
> >>
> >> On 12/7/2018 8:09 PM, Thomas Monjalon wrote:
> >>> 26/06/2018 11:23, David Hunt:
> >>>> This patch set adds the capability to do out-of-band power
> >>>> monitoring on a system. It uses a thread to monitor the branch
> >>>> counters in the targeted cores, and calculates the branch ratio
> >>>> if the running code.
> >>>>
> >>>> If the branch ratop is low (0.01), then
> >>>> the code is most likely running in a tight poll loop and doing
> >>>> nothing, i.e. receiving no packets. In this case we scale down
> >>>> the frequency of that core.
> >>>>
> >>>> If the branch ratio is higher (>0.01), then it is likely that
> >>>> the code is receiving and processing packets. In this case, we
> >>>> scale up the frequency of that core.
> >>>>
> >>>> The cpu counters are read via /dev/cpu/x/msr, so requires the
> >>>> msr kernel module to be loaded. Because this method is used,
> >>>> the patch set is implemented with one file for x86 systems, and
> >>>> another for non-x86 systems, with conditional compilation in
> >>>> the Makefile. The non-x86 functions are stubs, and do not
> >>>> currently implement any functionality.
> >>>>
> >>>> The vm_power_manager app has been modified to take a new parameter
> >>>> --core-list or -l
> >>>> which takes a list of cores in a comma-separated list format,
> >>>> e.g. 1,3,5-7,9, which resolvest to a core list of 1,3,5,6,7,9
> >>>> These cores will then be enabled for oob monitoring. When the
> >>>> OOB monitoring thread starts, it reads the branch hits/miss
> >>>> counters of each monitored core, and scales up/down accordingly.
> >>> It looks to be a feature which could be integrated in DPDK libs.
> >>> Why choosing to implement it fully in an example?
> >> I needed to set up a thread that looped tightly (~100uS interval) and
> >> run it on it's
> >> own core. From what I have seen in other cases, it is usually the
> >> application that
> >> allocates cores and decides what to run on them. I did think about putting
> >> some of it in a library, but for this case I thought it made more sense
> >> to keep
> >> it purely as a sample app.
> > I feel some code deserves to be in a library.
> > For instance, having different implementations per CPU is a good reason
> > to make a library.
> >
>
> Sure, I can look at moving some of the code into the library in a future
> release. However, I
> believe it's OK as it is for the current merge window.
I will to pull it in 18.08-rc2 if compilation is fine.
next prev parent reply other threads:[~2018-07-18 15:23 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-07 7:36 [dpdk-dev] [PATCH v1 0/6] " David Hunt
2018-06-07 7:37 ` [dpdk-dev] [PATCH v1 1/6] examples/vm_power: add check for port count David Hunt
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 0/8] examples/vm_power: 100% Busy Polling David Hunt
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 1/8] examples/vm_power: add check for port count David Hunt
2018-06-26 9:23 ` [dpdk-dev] [0/9] examples/vm_power: 100% Busy Polling David Hunt
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 1/9] examples/vm_power: add check for port count David Hunt
2018-07-13 14:22 ` [dpdk-dev] [PATCH v4 0/9] examples/vm_power: 100% Busy Polling David Hunt
2018-07-13 14:22 ` [dpdk-dev] [PATCH v4 1/9] examples/vm_power: add check for port count David Hunt
2018-07-13 14:22 ` [dpdk-dev] [PATCH v4 2/9] examples/vm_power: add core list parameter David Hunt
2018-07-13 14:22 ` [dpdk-dev] [PATCH v4 3/9] examples/vm_power: add oob monitoring functions David Hunt
2018-07-13 14:22 ` [dpdk-dev] [PATCH v4 4/9] examples/vm_power: allow greater than 64 cores David Hunt
2018-07-13 14:22 ` [dpdk-dev] [PATCH v4 5/9] examples/vm_power: add thread for oob core monitor David Hunt
2018-07-13 14:22 ` [dpdk-dev] [PATCH v4 6/9] examples/vm_power: add port-list to command line David Hunt
2018-07-13 14:23 ` [dpdk-dev] [PATCH v4 7/9] examples/vm_power: add branch ratio policy type David Hunt
2018-07-13 14:23 ` [dpdk-dev] [PATCH v4 8/9] examples/vm_power: add cli args to guest app David Hunt
2018-07-13 14:23 ` [dpdk-dev] [PATCH v4 9/9] examples/vm_power: make branch ratio configurable David Hunt
2018-07-20 22:06 ` [dpdk-dev] [PATCH v4 0/9] examples/vm_power: 100% Busy Polling Thomas Monjalon
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 2/9] examples/vm_power: add core list parameter David Hunt
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 3/9] examples/vm_power: add oob monitoring functions David Hunt
2018-07-12 19:13 ` Thomas Monjalon
2018-07-12 22:18 ` Stephen Hemminger
2018-07-13 8:24 ` Hunt, David
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 4/9] examples/vm_power: allow greater than 64 cores David Hunt
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 5/9] examples/vm_power: add thread for oob core monitor David Hunt
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 6/9] examples/vm_power: add port-list to command line David Hunt
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 7/9] examples/vm_power: add branch ratio policy type David Hunt
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 8/9] examples/vm_power: add cli args to guest app David Hunt
2018-06-26 9:23 ` [dpdk-dev] [PATCH v3 9/9] examples/vm_power: make branch ratio configurable David Hunt
2018-07-12 19:09 ` [dpdk-dev] [0/9] examples/vm_power: 100% Busy Polling Thomas Monjalon
2018-07-13 8:31 ` Hunt, David
2018-07-13 8:33 ` Thomas Monjalon
2018-07-13 8:43 ` Hunt, David
2018-07-18 15:23 ` Thomas Monjalon [this message]
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 2/8] examples/vm_power: add core list parameter David Hunt
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 3/8] examples/vm_power: add oob monitoring functions David Hunt
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 4/8] examples/vm_power: allow greater than 64 cores David Hunt
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 5/8] examples/vm_power: add thread for oob core monitor David Hunt
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 6/8] examples/vm_power: add port-list to command line David Hunt
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 7/8] examples/vm_power: add branch ratio policy type David Hunt
2018-06-21 13:24 ` [dpdk-dev] [PATCH v2 8/8] examples/vm_power: add cli args to guest app David Hunt
2018-06-21 14:28 ` [dpdk-dev] [PATCH v2 0/8] examples/vm_power: 100% Busy Polling Radu Nicolau
2018-06-07 7:37 ` [dpdk-dev] [PATCH v1 2/6] examples/vm_power: add core list parameter David Hunt
2018-06-07 7:37 ` [dpdk-dev] [PATCH v1 3/6] examples/vm_power: add oob monitoring functions David Hunt
2018-06-07 7:37 ` [dpdk-dev] [PATCH v1 4/6] examples/vm_power: allow greater than 64 cores David Hunt
2018-06-07 7:37 ` [dpdk-dev] [PATCH v1 5/6] examples/vm_power: add thread for oob core monitor David Hunt
2018-06-07 7:37 ` [dpdk-dev] [PATCH v1 6/6] examples/vm_power: add port-list to command line David Hunt
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