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Why emfc_kpr use high CPU in VIOS 3.1?

Question & Answer


After migration from VIOS 2.2 to 3.1, why the emfc_kpr process is one of the top processes CPU consumption the list?


The emfc_kpr process is a kernel process that was added for handling the 16Gb and higher speed fibre channel adapters.

Instead of processing the threads via the protocol driver (as it works in previous releases), emfc_kpr process is now processing them.

If there are virtual FC adapters configured in the environment (with VFC), then emfc_kpr works in conjunction with the npivk process.

The emfc_kpr process (and npivk process in NPIV / VFC environment) processes will consume CPU as I/O is moved/passed through.


They will not or should not negatively affect the system performance but rather opposite. The emfc_kpr is supposed to enhance the overall adapter driver performance.

In case when high IO throughput is in place we can expect it will need some CPU resources.

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Modified date:
26 November 2020