Re: [dpdk-dev] [PATCH v15 00/13] Interrupt mode PMD

["Liang, Cunming" <cunming.liang@intel.com>]

Hi Thomas and all,

This patch set postponed from v2.0, and widely reviewed during this release cycle.
The packet I/O interrupt framework is the prerequisite of all PMDs to support packet I/O intr.
There's no significant change since the last three version(v13~v15), the changes are about ABI and version map fixing.
It missed the rc1 in the last minutes, I'm now asking for the exception to make it go into v2.1 rc2 if nobody will reject it.
Again, thanks for all the comments by Stephen, David, Neil and Thomas.

Thanks,
Steve

> -----Original Message-----
> From: Liang, Cunming
> Sent: Monday, July 20, 2015 11:02 AM
> To: dev@dpdk.org; thomas.monjalon@6wind.com
> Cc: shemming@brocade.com; david.marchand@6wind.com; Zhou, Danny; Liu,
> Yong; nhorman@tuxdriver.com; Liang, Cunming
> Subject: [PATCH v15 00/13] Interrupt mode PMD
> 
> v15 changes
>  - remove unnecessary RTE_NEXT_ABI comment
>  - remove ifdef RTE_NEXT_ABI from header file
> 
> v14 changes
>  - per-patch basis ABI compatibility rework
>  - remove unnecessary 'local: *' from version map
>  - minor comments rework
> 
> v13 changes
>  - version map cleanup for v2.1
>  - replace RTE_EAL_RX_INTR by RTE_NEXT_ABI for ABI compatibility
> 
> Patch series v12
> Acked-by: Stephen Hemminger <stephen@networkplumber.org>
> Acked-by: Danny Zhou <danny.zhou@intel.com>
> 
> v12 changes
>  - bsd cleanup for unused variable warning
>  - fix awkward line split in debug message
> 
> v11 changes
>  - typo cleanup and check kernel style
> 
> v10 changes
>  - code rework to return actual error code
>  - bug fix for lsc when using uio_pci_generic
> 
> v9 changes
>  - code rework to fix open comment
>  - bug fix for igb lsc when both lsc and rxq are enabled in vfio-msix
>  - new patch to turn off the feature by default so as to avoid v2.1 abi broken
> 
> v8 changes
>  - remove condition check for only vfio-msix
>  - add multiplex intr support when only one intr vector allowed
>  - lsc and rxq interrupt runtime enable decision
>  - add safe event delete while the event wakeup execution happens
> 
> v7 changes
>  - decouple epoll event and intr operation
>  - add condition check in the case intr vector is disabled
>  - renaming some APIs
> 
> v6 changes
>  - split rte_intr_wait_rx_pkt into two APIs 'wait' and 'set'.
>  - rewrite rte_intr_rx_wait/rte_intr_rx_set.
>  - using vector number instead of queue_id as interrupt API params.
>  - patch reorder and split.
> 
> v5 changes
>  - Rebase the patchset onto the HEAD
>  - Isolate ethdev from EAL for new-added wait-for-rx interrupt function
>  - Export wait-for-rx interrupt function for shared libraries
>  - Split-off a new patch file for changed struct rte_intr_handle that
>    other patches depend on, to avoid breaking git bisect
>  - Change sample applicaiton to accomodate EAL function spec change
>    accordingly
> 
> v4 changes
>  - Export interrupt enable/disable functions for shared libraries
>  - Adjust position of new-added structure fields and functions to
>    avoid breaking ABI
> 
> v3 changes
>  - Add return value for interrupt enable/disable functions
>  - Move spinlok from PMD to L3fwd-power
>  - Remove unnecessary variables in e1000_mac_info
>  - Fix miscelleous review comments
> 
> v2 changes
>  - Fix compilation issue in Makefile for missed header file.
>  - Consolidate internal and community review comments of v1 patch set.
> 
> The patch series introduce low-latency one-shot rx interrupt into DPDK with
> polling and interrupt mode switch control example.
> 
> DPDK userspace interrupt notification and handling mechanism is based on UIO
> with below limitation:
> 1) It is designed to handle LSC interrupt only with inefficient suspended
>    pthread wakeup procedure (e.g. UIO wakes up LSC interrupt handling thread
>    which then wakes up DPDK polling thread). In this way, it introduces
>    non-deterministic wakeup latency for DPDK polling thread as well as packet
>    latency if it is used to handle Rx interrupt.
> 2) UIO only supports a single interrupt vector which has to been shared by
>    LSC interrupt and interrupts assigned to dedicated rx queues.
> 
> This patchset includes below features:
> 1) Enable one-shot rx queue interrupt in ixgbe PMD(PF & VF) and igb PMD(PF
> only)
> .
> 2) Build on top of the VFIO mechanism instead of UIO, so it could support
>    up to 64 interrupt vectors for rx queue interrupts.
> 3) Have 1 DPDK polling thread handle per Rx queue interrupt with a dedicated
>    VFIO eventfd, which eliminates non-deterministic pthread wakeup latency in
>    user space.
> 4) Demonstrate interrupts control APIs and userspace NAIP-like polling/interrupt
>    switch algorithms in L3fwd-power example.
> 
> Known limitations:
> 1) It does not work for UIO due to a single interrupt eventfd shared by LSC
>    and rx queue interrupt handlers causes a mess. [FIXED]
> 2) LSC interrupt is not supported by VF driver, so it is by default disabled
>    in L3fwd-power now. Feel free to turn in on if you want to support both LSC
>    and rx queue interrupts on a PF.
> 
> Cunming Liang (13):
>   eal/linux: add interrupt vectors support in intr_handle
>   eal/linux: add rte_epoll_wait/ctl support
>   eal/linux: add API to set rx interrupt event monitor
>   eal/linux: fix comments typo on vfio msi
>   eal/linux: map eventfd to VFIO MSI-X intr vector
>   eal/linux: standalone intr event fd create support
>   eal/linux: fix lsc read error in uio_pci_generic
>   eal/bsd: dummy for new intr definition
>   eal/bsd: fix inappropriate linuxapp referred in bsd
>   ethdev: add rx intr enable, disable and ctl functions
>   ixgbe: enable rx queue interrupts for both PF and VF
>   igb: enable rx queue interrupts for PF
>   l3fwd-power: enable one-shot rx interrupt and polling/interrupt mode
>     switch
> 
>  drivers/net/e1000/igb_ethdev.c                     | 311 ++++++++++--
>  drivers/net/ixgbe/ixgbe_ethdev.c                   | 527
> ++++++++++++++++++++-
>  drivers/net/ixgbe/ixgbe_ethdev.h                   |   4 +
>  examples/l3fwd-power/main.c                        | 205 ++++++--
>  lib/librte_eal/bsdapp/eal/eal_interrupts.c         |  42 ++
>  .../bsdapp/eal/include/exec-env/rte_interrupts.h   |  74 ++-
>  lib/librte_eal/bsdapp/eal/rte_eal_version.map      |   5 +
>  lib/librte_eal/linuxapp/eal/eal_interrupts.c       | 414 ++++++++++++++--
>  .../linuxapp/eal/include/exec-env/rte_interrupts.h | 153 ++++++
>  lib/librte_eal/linuxapp/eal/rte_eal_version.map    |   8 +
>  lib/librte_ether/rte_ethdev.c                      | 147 ++++++
>  lib/librte_ether/rte_ethdev.h                      | 104 ++++
>  lib/librte_ether/rte_ether_version.map             |   4 +
>  13 files changed, 1870 insertions(+), 128 deletions(-)
> 
> --
> 1.8.1.4