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| author | Jie Wang <wangjie125@huawei.com> | 2022-04-12 05:01:19 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-04-15 21:41:35 +0300 |
| commit | 4dc84c06a343fcb95fd5a0acb537aefa4ebdd1b0 (patch) | |
| tree | 1d4d2df174abd6f963ed1fb7a082e56e5725aded /Documentation/networking | |
| parent | 0a03f3c511f57da4d7159a150f1ab4b87f62c040 (diff) | |
| download | linux-4dc84c06a343fcb95fd5a0acb537aefa4ebdd1b0.tar.xz | |
net: ethtool: extend ringparam set/get APIs for tx_push
Currently tx push is a standard driver feature which controls use of a fast
path descriptor push. So this patch extends the ringparam APIs and data
structures to support set/get tx push by ethtool -G/g.
Signed-off-by: Jie Wang <wangjie125@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/ethtool-netlink.rst | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst index 24d9be69065d..dbca3e9ec782 100644 --- a/Documentation/networking/ethtool-netlink.rst +++ b/Documentation/networking/ethtool-netlink.rst @@ -862,6 +862,7 @@ Kernel response contents: ``ETHTOOL_A_RINGS_RX_BUF_LEN`` u32 size of buffers on the ring ``ETHTOOL_A_RINGS_TCP_DATA_SPLIT`` u8 TCP header / data split ``ETHTOOL_A_RINGS_CQE_SIZE`` u32 Size of TX/RX CQE + ``ETHTOOL_A_RINGS_TX_PUSH`` u8 flag of TX Push mode ==================================== ====== =========================== ``ETHTOOL_A_RINGS_TCP_DATA_SPLIT`` indicates whether the device is usable with @@ -871,6 +872,12 @@ separate buffers. The device configuration must make it possible to receive full memory pages of data, for example because MTU is high enough or through HW-GRO. +``ETHTOOL_A_RINGS_TX_PUSH`` flag is used to enable descriptor fast +path to send packets. In ordinary path, driver fills descriptors in DRAM and +notifies NIC hardware. In fast path, driver pushes descriptors to the device +through MMIO writes, thus reducing the latency. However, enabling this feature +may increase the CPU cost. Drivers may enforce additional per-packet +eligibility checks (e.g. on packet size). RINGS_SET ========= @@ -887,6 +894,7 @@ Request contents: ``ETHTOOL_A_RINGS_TX`` u32 size of TX ring ``ETHTOOL_A_RINGS_RX_BUF_LEN`` u32 size of buffers on the ring ``ETHTOOL_A_RINGS_CQE_SIZE`` u32 Size of TX/RX CQE + ``ETHTOOL_A_RINGS_TX_PUSH`` u8 flag of TX Push mode ==================================== ====== =========================== Kernel checks that requested ring sizes do not exceed limits reported by |