From: "Hunt, David" <david.hunt@intel.com>
To: Thomas Monjalon <thomas@monjalon.net>
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: Fri, 13 Jul 2018 09:31:38 +0100 [thread overview]
Message-ID: <efdefc9e-1318-cce4-3db6-61faf58cec1c@intel.com> (raw)
In-Reply-To: <2730584.abn78hPeQH@xps>
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.
Regards,
Dave.
next prev parent reply other threads:[~2018-07-13 8:29 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 [this message]
2018-07-13 8:33 ` Thomas Monjalon
2018-07-13 8:43 ` Hunt, David
2018-07-18 15:23 ` Thomas Monjalon
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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