On 3 August 2016 at 11:26, Yao, Lei A <lei.a.yao at intel.com> wrote: > Hi, Jianbo > > I have tested you patch on my X86 platform, the single core performance for > Non-vector PMD will have about 1Mpps drop > Non-vector PMD single core performance with patch : ~33.9 Mpps > Non-vector PMD single core performance without patch : ~35.1 Mpps > Is there any way to avoid such performance drop on X86? Thanks. >
I think we can place a compiling condition before rte_rmb() to avoid performance decrease on x86. For example: #if defined(RTE_ARCH_ARM) || defined(RTE_ARCH_ARM64) Thanks! Jianbo > BRs > Lei > > -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Jianbo Liu > Sent: Tuesday, August 2, 2016 2:58 PM > To: dev at dpdk.org; Zhang, Helin <helin.zhang at intel.com>; Wu, Jingjing > <jingjing.wu at intel.com> > Cc: Jianbo Liu <jianbo.liu at linaro.org> > Subject: [dpdk-dev] [PATCH] i40e: enable i40e pmd on ARM platform > > And add read memory barrier to avoid status inconsistency between two RX > descriptors readings. > > Signed-off-by: Jianbo Liu <jianbo.liu at linaro.org> > --- > config/defconfig_arm64-armv8a-linuxapp-gcc | 2 +- > doc/guides/nics/overview.rst | 2 +- > drivers/net/i40e/i40e_rxtx.c | 2 ++ > 3 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/config/defconfig_arm64-armv8a-linuxapp-gcc > b/config/defconfig_arm64-armv8a-linuxapp-gcc > index 1a17126..08f282b 100644 > --- a/config/defconfig_arm64-armv8a-linuxapp-gcc > +++ b/config/defconfig_arm64-armv8a-linuxapp-gcc > @@ -46,6 +46,6 @@ CONFIG_RTE_EAL_IGB_UIO=n > > CONFIG_RTE_LIBRTE_IVSHMEM=n > CONFIG_RTE_LIBRTE_FM10K_PMD=n > -CONFIG_RTE_LIBRTE_I40E_PMD=n > +CONFIG_RTE_LIBRTE_I40E_INC_VECTOR=n > > CONFIG_RTE_SCHED_VECTOR=n > diff --git a/doc/guides/nics/overview.rst b/doc/guides/nics/overview.rst > index 6abbae6..5175591 100644 > --- a/doc/guides/nics/overview.rst > +++ b/doc/guides/nics/overview.rst > @@ -138,7 +138,7 @@ Most of these differences are summarized below. > Linux VFIO Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y > Y Y Y > Other kdrv Y Y > Y > ARMv7 > Y Y Y > - ARMv8 Y Y Y Y > Y Y Y Y > + ARMv8 Y Y Y Y Y > Y Y Y Y > Power8 Y Y > Y > TILE-Gx > Y > x86-32 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y > Y Y Y Y > diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c > index 554d167..4004b8e 100644 > --- a/drivers/net/i40e/i40e_rxtx.c > +++ b/drivers/net/i40e/i40e_rxtx.c > @@ -994,6 +994,8 @@ i40e_rx_scan_hw_ring(struct i40e_rx_queue *rxq) > I40E_RXD_QW1_STATUS_SHIFT; > } > > + rte_rmb(); > + > /* Compute how many status bits were set */ > for (j = 0, nb_dd = 0; j < I40E_LOOK_AHEAD; j++) > nb_dd += s[j] & (1 << I40E_RX_DESC_STATUS_DD_SHIFT); > -- > 2.4.11 >
