| Message ID | 20170606150041.10955-16-ruxandra.radulescu@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jun 06, 2017 at 10:00:38AM -0500, Ioana Radulescu wrote: > Reorder fields in the device's private structure such that > the ones most used on the hotpath are at the beginning of > the structure. > > This brings a small performance improvement due to better > cache usage. Really? What kind of performance improvement? Always be specific. Please fix up and resend. thanks, greg k-h
> -----Original Message----- > From: Greg KH [mailto:gregkh@linuxfoundation.org] > Sent: Tuesday, June 13, 2017 1:04 PM > To: Ruxandra Ioana Radulescu <ruxandra.radulescu@nxp.com> > Cc: devel@driverdev.osuosl.org; stuyoder@gmail.com; arnd@arndb.de; > linux-kernel@vger.kernel.org; agraf@suse.de; Bharat Bhushan > <bharat.bhushan@nxp.com>; Bogdan Purcareata > <bogdan.purcareata@nxp.com>; linux-arm-kernel@lists.infradead.org; > Laurentiu Tudor <laurentiu.tudor@nxp.com> > Subject: Re: [PATCH 15/18] staging: fsl-dpaa2/eth: Reorder priv fields > > On Tue, Jun 06, 2017 at 10:00:38AM -0500, Ioana Radulescu wrote: > > Reorder fields in the device's private structure such that > > the ones most used on the hotpath are at the beginning of > > the structure. > > > > This brings a small performance improvement due to better > > cache usage. > > Really? What kind of performance improvement? Always be specific. Fair point, thanks. The test scenario was ipfwd with small frames and the improvement ~1%, but I took this patch from an internal repo, so I need to redo the measurements on the current tree before resending. > > Please fix up and resend. We're preparing a larger patchset with several optimizations, I'll probably include the v2 there. Thanks, Ioana
diff --git a/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h b/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h index 886a0681fee1..c760e9b77e22 100644 --- a/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h +++ b/drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h @@ -290,34 +290,30 @@ struct dpaa2_eth_hash_fields { /* Driver private data */ struct dpaa2_eth_priv { struct net_device *net_dev; + /* Standard statistics */ + struct rtnl_link_stats64 __percpu *percpu_stats; + /* Extra stats, in addition to the ones known by the kernel */ + struct dpaa2_eth_drv_stats __percpu *percpu_extras; + struct iommu_domain *iommu_domain; + u16 tx_data_offset; + u16 bpid; + u16 tx_qdid; u8 num_fqs; - struct dpaa2_eth_fq fq[DPAA2_ETH_MAX_QUEUES]; - u8 num_channels; + struct dpaa2_eth_fq fq[DPAA2_ETH_MAX_QUEUES]; struct dpaa2_eth_channel *channel[DPAA2_ETH_MAX_DPCONS]; + struct fsl_mc_io *mc_io; + u16 mc_token; struct dpni_attr dpni_attrs; - u16 tx_data_offset; - struct fsl_mc_device *dpbp_dev; - u16 bpid; - struct iommu_domain *iommu_domain; - u16 tx_qdid; - struct fsl_mc_io *mc_io; /* Cores which have an affine DPIO/DPCON. * This is the cpu set on which Rx and Tx conf frames are processed */ struct cpumask dpio_cpumask; - /* Standard statistics */ - struct rtnl_link_stats64 __percpu *percpu_stats; - /* Extra stats, in addition to the ones known by the kernel */ - struct dpaa2_eth_drv_stats __percpu *percpu_extras; - - u16 mc_token; - struct dpni_link_state link_state; bool do_link_poll; struct task_struct *poll_thread;
Reorder fields in the device's private structure such that the ones most used on the hotpath are at the beginning of the structure. This brings a small performance improvement due to better cache usage. Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com> --- drivers/staging/fsl-dpaa2/ethernet/dpaa2-eth.h | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-)