From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v2 1/3] doc: updated i40e enabling additonal fnct in gsg Date: Fri, 19 Dec 2014 22:42:26 +0100 Message-ID: <5161014.FHTZczFVPs@xps13> References: <1417563667-16686-1-git-send-email-siobhan.a.butler@intel.com> <1419001728-7878-1-git-send-email-pablo.de.lara.guarch@intel.com> <1419001728-7878-2-git-send-email-pablo.de.lara.guarch@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit To: dev-VfR2kkLFssw@public.gmane.org Return-path: In-Reply-To: <1419001728-7878-2-git-send-email-pablo.de.lara.guarch-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" > --- a/doc/guides/linux_gsg/enable_func.rst > +++ b/doc/guides/linux_gsg/enable_func.rst > @@ -171,6 +171,10 @@ Please note that while using iommu=pt is compulsory for igb_uio driver, the vfio > High Performance of Small Packets on 40G NIC > -------------------------------------------- > > +As there might be firmware fixes for performance enhancement in latest version > +of firmware image, the firmware update might be needed for getting high performance. > +Check with the local Intel's Network Division application engineers for firmware updates. > + > Enabling Extended Tag and Setting Max Read Request Size > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > @@ -198,3 +202,13 @@ Use 16 Bytes RX Descriptor Size > > As i40e PMD supports both 16 and 32 bytes RX descriptor sizes, and 16 bytes size can provide helps to high performance of small packets. > Configuration of CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC in config files can be changed to use 16 bytes size RX descriptors. > + > +High Performance and per Packet Latency Tradeoff > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +Due to the hardware design, the interrupt signal inside NIC is needed for per > +packet descriptor write-back. The minimum interval of interrupts could be set > +at compile time by CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL in configuration files. > +Though there is a default configuration, the interval could be tuned by the > +users with that configuration item depends on what the user cares about more, > +performance or per packet latency. This kind of hardware information is not specific to Linux. I think we should open some guides dedicated to drivers design. Examples: - doc/guides/drivers/i40e/ - doc/guides/drivers/enic/ - etc Any volunteer to start this new doc directory? -- Thomas