X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=doc%2Fguides%2Fsample_app_ug%2Fvm_power_management.rst;h=1b6de8e93636848ece04f105a1e9a53b27e0e602;hb=483a914d24a01683c8c450a6314109b7f6d35568;hp=e98277ccb0a0cb9a0fb2e84708dc3e0f46b07bca;hpb=d7decefc37244adb1e1c40249b8eb147e0410360;p=dpdk.git diff --git a/doc/guides/sample_app_ug/vm_power_management.rst b/doc/guides/sample_app_ug/vm_power_management.rst index e98277ccb0..1b6de8e936 100644 --- a/doc/guides/sample_app_ug/vm_power_management.rst +++ b/doc/guides/sample_app_ug/vm_power_management.rst @@ -410,19 +410,21 @@ There are a couple of command line parameters for enabling the out-of-band monitoring of branch ratios on cores doing busy polling using PMDs as described below: -``--core-list {list of cores}`` +``--core-branch-ratio {list of cores}:{branch ratio for listed cores}`` Specify the list of cores to monitor the ratio of branch misses to branch hits. A tightly-polling PMD thread has a very low branch ratio, therefore the core frequency scales down to the minimum allowed value. On receiving packets, the code path changes, causing the branch ratio to increase. When the ratio goes above the ratio threshold, the core frequency scales up to the maximum - allowed value. - -``--branch-ratio {ratio}`` - Specify a floating-point number that identifies the threshold at which - to scale up or down for the given workload. The default branch ratio - is 0.01 and needs adjustment for different workloads. + allowed value. The specified branch-ratio is a floating point number + that identifies the threshold at which to scale up or down for the + elements of the core-list. If not included the default branch ratio of + 0.01 but will need adjustment for different workloads + + This parameter can be used multiple times for different sets of cores. + The branch ratio mechanism can also be useful for non-PMD cores and + hyper-threaded environments where C-States are disabled. Compiling and Running the Guest Applications