From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v6 0/3] DPDK ethdev callback support Date: Tue, 24 Feb 2015 00:39:58 +0100 Message-ID: <2169176.yPx3Hmtc39@xps13> References: <1424281343-2994-1-git-send-email-john.mcnamara@intel.com> <1424716210-25773-1-git-send-email-john.mcnamara@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev-VfR2kkLFssw@public.gmane.org To: John McNamara , bruce.richardson-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org Return-path: In-Reply-To: <1424716210-25773-1-git-send-email-john.mcnamara-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" 2015-02-23 18:30, John McNamara: > This patchset is for a small optional addition to the ethdev library, > to add support for callbacks at the RX and TX stages. This allows > packet processing to be done on packets before they get returned > to applications using rte_eth_rx_burst call. > > See the RFC cover letter for the use cases: > > http://dpdk.org/ml/archives/dev/2014-December/010491.html > > For this version we spent some time investigating Stephen Hemminger's > suggestion of using the userspace RCU (read-copy-update) library for > SMP safety: > > http://urcu.so/ > > The default liburcu (which defaulted to liburcu-mb) requires the least > interaction from the end user but showed a 25% drop in packet throughput > in the callback sample app. > > The liburcu-qsbr (quiescent state) variant showed a 1% drop in packet > throughput in the callback sample app. However it requires registered > RCU threads in the program to periodically announce quiescent states. > This makes it more difficult to implement for end user applications. > > For this release we will document that adding and removing callbacks > is not thread safe. > > Note: Sample application documentation to follow in a patch update. > > Version 6 changes: > * RX/TX callback functions are no longer #ifdefed out if callback > option is off. Instead they return ENOTSUP. > * Simplified callbacks #ifdefs in rte_ethdev. > > Version 5 changes: > * Turned the callback feature on by default. > * Simplified #define name. > > Version 4 changes: > * Made the callback feature a compile time option. > > Version 3 changes: > * Removed unnecessary header file from example folder > (which included baremetal reference). > * Renamed the interrupt, RX and TX callbacks to make their function > clearer (using the names suggested in the mailing list comments). > * Squashed ABI version update into the commit it relates to. > * Fixed various checkpatch warnings. > > Version 2 changes: > * Added ABI versioning. > * Doxygen clarifications. > > Version 1 changes: > * Added callback removal functions. > * Minor fixes. > > Richardson, Bruce (3): > ethdev: rename callbacks field to link_intr_cbs > ethdev: add optional rxtx callback support > examples: example showing use of callbacks. Applied, thanks