| Message ID | 20241031002326.3426181-2-csander@purestorage.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [resend,1/2] dim: make dim_calc_stats() inputs const pointers | expand |
On Wed, Oct 30, 2024 at 06:23:26PM -0600, Caleb Sander Mateos wrote: > net_dim() is currently passed a struct dim_sample argument by value. > struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 > passes it on the stack. All callers have already initialized dim_sample > on the stack, so passing it by value requires pushing a duplicated copy > to the stack. Either witing to the stack and immediately reading it, or > perhaps dereferencing addresses relative to the stack pointer in a chain > of push instructions, seems to perform quite poorly. > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > 94% of which is attributed to the first push instruction to copy > dim_sample on the stack for the call to net_dim(): > // Call ktime_get() > 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> > // Pass the address of struct dim in %rdi > |4ead7: lea 0x3d0(%rbx),%rdi > // Set dim_sample.pkt_ctr > |4eade: mov %r13d,0x8(%rsp) > // Set dim_sample.byte_ctr > |4eae3: mov %r12d,0xc(%rsp) > // Set dim_sample.event_ctr > 0.15 |4eae8: mov %bp,0x10(%rsp) > // Duplicate dim_sample on the stack > 94.16 |4eaed: push 0x10(%rsp) > 2.79 |4eaf1: push 0x10(%rsp) > 0.07 |4eaf5: push %rax > // Call net_dim() > 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> > > To allow the caller to reuse the struct dim_sample already on the stack, > pass the struct dim_sample by reference to net_dim(). > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> > --- > Documentation/networking/net_dim.rst | 2 +- > drivers/net/ethernet/amazon/ena/ena_netdev.c | 2 +- > drivers/net/ethernet/broadcom/bcmsysport.c | 2 +- > drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++-- > drivers/net/ethernet/broadcom/genet/bcmgenet.c | 2 +- > drivers/net/ethernet/freescale/enetc/enetc.c | 2 +- > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 4 ++-- > drivers/net/ethernet/intel/ice/ice_txrx.c | 4 ++-- > drivers/net/ethernet/intel/idpf/idpf_txrx.c | 4 ++-- > drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 2 +- > drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++-- > drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c | 4 ++-- > drivers/net/ethernet/netronome/nfp/nfd3/dp.c | 4 ++-- > drivers/net/ethernet/netronome/nfp/nfdk/dp.c | 4 ++-- > drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 2 +- > drivers/net/virtio_net.c | 2 +- > drivers/soc/fsl/dpio/dpio-service.c | 2 +- > include/linux/dim.h | 2 +- > lib/dim/net_dim.c | 10 +++++----- > 19 files changed, 31 insertions(+), 31 deletions(-) > --- snip -- > diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > index d215efc6cad0..f1c6c47564b1 100644 > --- a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > +++ b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > @@ -1177,11 +1177,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > pkts = r_vec->rx_pkts; > bytes = r_vec->rx_bytes; > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->rx_dim, dim_sample); > + net_dim(&r_vec->rx_dim, &dim_sample); > } > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > struct dim_sample dim_sample = {}; > unsigned int start; > @@ -1192,11 +1192,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > pkts = r_vec->tx_pkts; > bytes = r_vec->tx_bytes; > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->tx_dim, dim_sample); > + net_dim(&r_vec->tx_dim, &dim_sample); > } > > return pkts_polled; > } > > diff --git a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > index dae5af7d1845..ebeb6ab4465c 100644 > --- a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > +++ b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > @@ -1287,11 +1287,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > pkts = r_vec->rx_pkts; > bytes = r_vec->rx_bytes; > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->rx_dim, dim_sample); > + net_dim(&r_vec->rx_dim, &dim_sample); > } > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > struct dim_sample dim_sample = {}; > unsigned int start; > @@ -1302,11 +1302,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > pkts = r_vec->tx_pkts; > bytes = r_vec->tx_bytes; > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->tx_dim, dim_sample); > + net_dim(&r_vec->tx_dim, &dim_sample); > } > > return pkts_polled; > } --- snip --- Hi Caleb. Looks like a fair enough update to me in general, but I am not an expert on 'dim'. For the corresponding nfp driver changes feel free to add: Signed-off-by: Louis Peens <louis.peens@corigine.com>
On Wed, Oct 30, 2024 at 06:23:26PM -0600, Caleb Sander Mateos wrote: > net_dim() is currently passed a struct dim_sample argument by value. > struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 > passes it on the stack. All callers have already initialized dim_sample > on the stack, so passing it by value requires pushing a duplicated copy > to the stack. Either witing to the stack and immediately reading it, or > perhaps dereferencing addresses relative to the stack pointer in a chain > of push instructions, seems to perform quite poorly. > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > 94% of which is attributed to the first push instruction to copy > dim_sample on the stack for the call to net_dim(): > // Call ktime_get() > 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> > // Pass the address of struct dim in %rdi > |4ead7: lea 0x3d0(%rbx),%rdi > // Set dim_sample.pkt_ctr > |4eade: mov %r13d,0x8(%rsp) > // Set dim_sample.byte_ctr > |4eae3: mov %r12d,0xc(%rsp) > // Set dim_sample.event_ctr > 0.15 |4eae8: mov %bp,0x10(%rsp) > // Duplicate dim_sample on the stack > 94.16 |4eaed: push 0x10(%rsp) > 2.79 |4eaf1: push 0x10(%rsp) > 0.07 |4eaf5: push %rax > // Call net_dim() > 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> > > To allow the caller to reuse the struct dim_sample already on the stack, > pass the struct dim_sample by reference to net_dim(). > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> > --- Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
On 10/30/2024 5:23 PM, Caleb Sander Mateos wrote: > > net_dim() is currently passed a struct dim_sample argument by value. > struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 > passes it on the stack. All callers have already initialized dim_sample > on the stack, so passing it by value requires pushing a duplicated copy > to the stack. Either witing to the stack and immediately reading it, or > perhaps dereferencing addresses relative to the stack pointer in a chain > of push instructions, seems to perform quite poorly. > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > 94% of which is attributed to the first push instruction to copy > dim_sample on the stack for the call to net_dim(): > // Call ktime_get() > 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> > // Pass the address of struct dim in %rdi > |4ead7: lea 0x3d0(%rbx),%rdi > // Set dim_sample.pkt_ctr > |4eade: mov %r13d,0x8(%rsp) > // Set dim_sample.byte_ctr > |4eae3: mov %r12d,0xc(%rsp) > // Set dim_sample.event_ctr > 0.15 |4eae8: mov %bp,0x10(%rsp) > // Duplicate dim_sample on the stack > 94.16 |4eaed: push 0x10(%rsp) > 2.79 |4eaf1: push 0x10(%rsp) > 0.07 |4eaf5: push %rax > // Call net_dim() > 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> > > To allow the caller to reuse the struct dim_sample already on the stack, > pass the struct dim_sample by reference to net_dim(). > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> > --- > Documentation/networking/net_dim.rst | 2 +- > drivers/net/ethernet/amazon/ena/ena_netdev.c | 2 +- > drivers/net/ethernet/broadcom/bcmsysport.c | 2 +- > drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++-- > drivers/net/ethernet/broadcom/genet/bcmgenet.c | 2 +- > drivers/net/ethernet/freescale/enetc/enetc.c | 2 +- > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 4 ++-- > drivers/net/ethernet/intel/ice/ice_txrx.c | 4 ++-- > drivers/net/ethernet/intel/idpf/idpf_txrx.c | 4 ++-- > drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 2 +- > drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++-- > drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c | 4 ++-- > drivers/net/ethernet/netronome/nfp/nfd3/dp.c | 4 ++-- > drivers/net/ethernet/netronome/nfp/nfdk/dp.c | 4 ++-- > drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 2 +- for the pensando/ionic bits: Reviewed-by: Shannon Nelson <shannon.nelson@amd.com> > drivers/net/virtio_net.c | 2 +- > drivers/soc/fsl/dpio/dpio-service.c | 2 +- > include/linux/dim.h | 2 +- > lib/dim/net_dim.c | 10 +++++----- > 19 files changed, 31 insertions(+), 31 deletions(-) > > diff --git a/Documentation/networking/net_dim.rst b/Documentation/networking/net_dim.rst > index 8908fd7b0a8d..4377998e6826 100644 > --- a/Documentation/networking/net_dim.rst > +++ b/Documentation/networking/net_dim.rst > @@ -154,11 +154,11 @@ usage is not complete but it should make the outline of the usage clear. > dim_update_sample(my_entity->events, > my_entity->packets, > my_entity->bytes, > &dim_sample); > /* Call net DIM */ > - net_dim(&my_entity->dim, dim_sample); > + net_dim(&my_entity->dim, &dim_sample); > ... > } > > /* My entity's initialization function (my_entity was already allocated) */ > int my_driver_init_my_entity(struct my_driver_entity *my_entity, ...) > diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c > index 96df20854eb9..63c8a2328142 100644 > --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c > +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c > @@ -1381,11 +1381,11 @@ static void ena_adjust_adaptive_rx_intr_moderation(struct ena_napi *ena_napi) > dim_update_sample(rx_ring->non_empty_napi_events, > rx_ring->rx_stats.cnt, > rx_ring->rx_stats.bytes, > &dim_sample); > > - net_dim(&ena_napi->dim, dim_sample); > + net_dim(&ena_napi->dim, &dim_sample); > > rx_ring->per_napi_packets = 0; > } > > void ena_unmask_interrupt(struct ena_ring *tx_ring, > diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c > index caff6e87a488..031e9e0cca53 100644 > --- a/drivers/net/ethernet/broadcom/bcmsysport.c > +++ b/drivers/net/ethernet/broadcom/bcmsysport.c > @@ -1027,11 +1027,11 @@ static int bcm_sysport_poll(struct napi_struct *napi, int budget) > } > > if (priv->dim.use_dim) { > dim_update_sample(priv->dim.event_ctr, priv->dim.packets, > priv->dim.bytes, &dim_sample); > - net_dim(&priv->dim.dim, dim_sample); > + net_dim(&priv->dim.dim, &dim_sample); > } > > return work_done; > } > > diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c > index 6dd6541d8619..ca42b81133d7 100644 > --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c > +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c > @@ -3100,11 +3100,11 @@ static int bnxt_poll(struct napi_struct *napi, int budget) > > dim_update_sample(cpr->event_ctr, > cpr->rx_packets, > cpr->rx_bytes, > &dim_sample); > - net_dim(&cpr->dim, dim_sample); > + net_dim(&cpr->dim, &dim_sample); > } > return work_done; > } > > static int __bnxt_poll_cqs(struct bnxt *bp, struct bnxt_napi *bnapi, int budget) > @@ -3231,11 +3231,11 @@ static int bnxt_poll_p5(struct napi_struct *napi, int budget) > > dim_update_sample(cpr->event_ctr, > cpr_rx->rx_packets, > cpr_rx->rx_bytes, > &dim_sample); > - net_dim(&cpr->dim, dim_sample); > + net_dim(&cpr->dim, &dim_sample); > } > return work_done; > } > > static void bnxt_free_tx_skbs(struct bnxt *bp) > diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c > index 10966ab15373..53a949eb9180 100644 > --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c > +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c > @@ -2403,11 +2403,11 @@ static int bcmgenet_rx_poll(struct napi_struct *napi, int budget) > } > > if (ring->dim.use_dim) { > dim_update_sample(ring->dim.event_ctr, ring->dim.packets, > ring->dim.bytes, &dim_sample); > - net_dim(&ring->dim.dim, dim_sample); > + net_dim(&ring->dim.dim, &dim_sample); > } > > return work_done; > } > > diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c > index c09370eab319..05dedea6185a 100644 > --- a/drivers/net/ethernet/freescale/enetc/enetc.c > +++ b/drivers/net/ethernet/freescale/enetc/enetc.c > @@ -716,11 +716,11 @@ static void enetc_rx_net_dim(struct enetc_int_vector *v) > > dim_update_sample(v->comp_cnt, > v->rx_ring.stats.packets, > v->rx_ring.stats.bytes, > &dim_sample); > - net_dim(&v->rx_dim, dim_sample); > + net_dim(&v->rx_dim, &dim_sample); > } > > static int enetc_bd_ready_count(struct enetc_bdr *tx_ring, int ci) > { > int pi = enetc_rd_reg_hot(tx_ring->tcir) & ENETC_TBCIR_IDX_MASK; > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > index 4cbc4d069a1f..43377a7b2426 100644 > --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > @@ -4446,11 +4446,11 @@ static void hns3_update_rx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) > if (!rx_group->coal.adapt_enable) > return; > > dim_update_sample(tqp_vector->event_cnt, rx_group->total_packets, > rx_group->total_bytes, &sample); > - net_dim(&rx_group->dim, sample); > + net_dim(&rx_group->dim, &sample); > } > > static void hns3_update_tx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) > { > struct hns3_enet_ring_group *tx_group = &tqp_vector->tx_group; > @@ -4459,11 +4459,11 @@ static void hns3_update_tx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) > if (!tx_group->coal.adapt_enable) > return; > > dim_update_sample(tqp_vector->event_cnt, tx_group->total_packets, > tx_group->total_bytes, &sample); > - net_dim(&tx_group->dim, sample); > + net_dim(&tx_group->dim, &sample); > } > > static int hns3_nic_common_poll(struct napi_struct *napi, int budget) > { > struct hns3_nic_priv *priv = netdev_priv(napi->dev); > diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c > index 8208055d6e7f..5d2d7736fd5f 100644 > --- a/drivers/net/ethernet/intel/ice/ice_txrx.c > +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c > @@ -1350,18 +1350,18 @@ static void ice_net_dim(struct ice_q_vector *q_vector) > > if (ITR_IS_DYNAMIC(tx)) { > struct dim_sample dim_sample; > > __ice_update_sample(q_vector, tx, &dim_sample, true); > - net_dim(&tx->dim, dim_sample); > + net_dim(&tx->dim, &dim_sample); > } > > if (ITR_IS_DYNAMIC(rx)) { > struct dim_sample dim_sample; > > __ice_update_sample(q_vector, rx, &dim_sample, false); > - net_dim(&rx->dim, dim_sample); > + net_dim(&rx->dim, &dim_sample); > } > } > > /** > * ice_buildreg_itr - build value for writing to the GLINT_DYN_CTL register > diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c > index d4e6f0e10487..da2a5becf62f 100644 > --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c > +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c > @@ -3677,11 +3677,11 @@ static void idpf_net_dim(struct idpf_q_vector *q_vector) > } while (u64_stats_fetch_retry(&txq->stats_sync, start)); > } > > idpf_update_dim_sample(q_vector, &dim_sample, &q_vector->tx_dim, > packets, bytes); > - net_dim(&q_vector->tx_dim, dim_sample); > + net_dim(&q_vector->tx_dim, &dim_sample); > > check_rx_itr: > if (!IDPF_ITR_IS_DYNAMIC(q_vector->rx_intr_mode)) > return; > > @@ -3696,11 +3696,11 @@ static void idpf_net_dim(struct idpf_q_vector *q_vector) > } while (u64_stats_fetch_retry(&rxq->stats_sync, start)); > } > > idpf_update_dim_sample(q_vector, &dim_sample, &q_vector->rx_dim, > packets, bytes); > - net_dim(&q_vector->rx_dim, dim_sample); > + net_dim(&q_vector->rx_dim, &dim_sample); > } > > /** > * idpf_vport_intr_update_itr_ena_irq - Update itr and re-enable MSIX interrupt > * @q_vector: q_vector for which itr is being updated and interrupt enabled > diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c > index 933e18ba2fb2..7aaf32e9aa95 100644 > --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c > +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c > @@ -525,11 +525,11 @@ static void otx2_adjust_adaptive_coalese(struct otx2_nic *pfvf, struct otx2_cq_p > > dim_update_sample(pfvf->napi_events, > rx_frames + tx_frames, > rx_bytes + tx_bytes, > &dim_sample); > - net_dim(&cq_poll->dim, dim_sample); > + net_dim(&cq_poll->dim, &dim_sample); > } > > int otx2_napi_handler(struct napi_struct *napi, int budget) > { > struct otx2_cq_queue *rx_cq = NULL; > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c > index f01ceee5f02d..53485142938c 100644 > --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c > +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c > @@ -2225,11 +2225,11 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget, > > eth->rx_packets += done; > eth->rx_bytes += bytes; > dim_update_sample(eth->rx_events, eth->rx_packets, eth->rx_bytes, > &dim_sample); > - net_dim(ð->rx_dim, dim_sample); > + net_dim(ð->rx_dim, &dim_sample); > > if (xdp_flush) > xdp_do_flush(); > > return done; > @@ -2375,11 +2375,11 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget) > if (state.txq) > netdev_tx_completed_queue(state.txq, state.done, state.bytes); > > dim_update_sample(eth->tx_events, eth->tx_packets, eth->tx_bytes, > &dim_sample); > - net_dim(ð->tx_dim, dim_sample); > + net_dim(ð->tx_dim, &dim_sample); > > if (mtk_queue_stopped(eth) && > (atomic_read(&ring->free_count) > ring->thresh)) > mtk_wake_queue(eth); > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c > index 5873fde65c2e..417098f0b2bb 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c > @@ -53,11 +53,11 @@ static void mlx5e_handle_tx_dim(struct mlx5e_txqsq *sq) > > if (unlikely(!test_bit(MLX5E_SQ_STATE_DIM, &sq->state))) > return; > > dim_update_sample(sq->cq.event_ctr, stats->packets, stats->bytes, &dim_sample); > - net_dim(sq->dim, dim_sample); > + net_dim(sq->dim, &dim_sample); > } > > static void mlx5e_handle_rx_dim(struct mlx5e_rq *rq) > { > struct mlx5e_rq_stats *stats = rq->stats; > @@ -65,11 +65,11 @@ static void mlx5e_handle_rx_dim(struct mlx5e_rq *rq) > > if (unlikely(!test_bit(MLX5E_RQ_STATE_DIM, &rq->state))) > return; > > dim_update_sample(rq->cq.event_ctr, stats->packets, stats->bytes, &dim_sample); > - net_dim(rq->dim, dim_sample); > + net_dim(rq->dim, &dim_sample); > } > > void mlx5e_trigger_irq(struct mlx5e_icosq *sq) > { > struct mlx5_wq_cyc *wq = &sq->wq; > diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > index d215efc6cad0..f1c6c47564b1 100644 > --- a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > +++ b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > @@ -1177,11 +1177,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > pkts = r_vec->rx_pkts; > bytes = r_vec->rx_bytes; > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->rx_dim, dim_sample); > + net_dim(&r_vec->rx_dim, &dim_sample); > } > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > struct dim_sample dim_sample = {}; > unsigned int start; > @@ -1192,11 +1192,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > pkts = r_vec->tx_pkts; > bytes = r_vec->tx_bytes; > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->tx_dim, dim_sample); > + net_dim(&r_vec->tx_dim, &dim_sample); > } > > return pkts_polled; > } > > diff --git a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > index dae5af7d1845..ebeb6ab4465c 100644 > --- a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > +++ b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > @@ -1287,11 +1287,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > pkts = r_vec->rx_pkts; > bytes = r_vec->rx_bytes; > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->rx_dim, dim_sample); > + net_dim(&r_vec->rx_dim, &dim_sample); > } > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > struct dim_sample dim_sample = {}; > unsigned int start; > @@ -1302,11 +1302,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > pkts = r_vec->tx_pkts; > bytes = r_vec->tx_bytes; > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->tx_dim, dim_sample); > + net_dim(&r_vec->tx_dim, &dim_sample); > } > > return pkts_polled; > } > > diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c > index 0eeda7e502db..2ac59564ded1 100644 > --- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c > +++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c > @@ -926,11 +926,11 @@ static void ionic_dim_update(struct ionic_qcq *qcq, int napi_mode) > } > > dim_update_sample(qcq->cq.bound_intr->rearm_count, > pkts, bytes, &dim_sample); > > - net_dim(&qcq->dim, dim_sample); > + net_dim(&qcq->dim, &dim_sample); > } > > int ionic_tx_napi(struct napi_struct *napi, int budget) > { > struct ionic_qcq *qcq = napi_to_qcq(napi); > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 792e9eadbfc3..869586c17ffd 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -2802,11 +2802,11 @@ static void virtnet_rx_dim_update(struct virtnet_info *vi, struct receive_queue > dim_update_sample(rq->calls, > u64_stats_read(&rq->stats.packets), > u64_stats_read(&rq->stats.bytes), > &cur_sample); > > - net_dim(&rq->dim, cur_sample); > + net_dim(&rq->dim, &cur_sample); > rq->packets_in_napi = 0; > } > > static int virtnet_poll(struct napi_struct *napi, int budget) > { > diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c > index b811446e0fa5..0b60ed16297c 100644 > --- a/drivers/soc/fsl/dpio/dpio-service.c > +++ b/drivers/soc/fsl/dpio/dpio-service.c > @@ -889,10 +889,10 @@ void dpaa2_io_update_net_dim(struct dpaa2_io *d, __u64 frames, __u64 bytes) > > d->bytes += bytes; > d->frames += frames; > > dim_update_sample(d->event_ctr, d->frames, d->bytes, &dim_sample); > - net_dim(&d->rx_dim, dim_sample); > + net_dim(&d->rx_dim, &dim_sample); > > spin_unlock(&d->dim_lock); > } > EXPORT_SYMBOL(dpaa2_io_update_net_dim); > diff --git a/include/linux/dim.h b/include/linux/dim.h > index 84579a50ae7f..06543fd40fcc 100644 > --- a/include/linux/dim.h > +++ b/include/linux/dim.h > @@ -423,11 +423,11 @@ struct dim_cq_moder net_dim_get_def_tx_moderation(u8 cq_period_mode); > * > * Called by the consumer. > * This is the main logic of the algorithm, where data is processed in order > * to decide on next required action. > */ > -void net_dim(struct dim *dim, struct dim_sample end_sample); > +void net_dim(struct dim *dim, const struct dim_sample *end_sample); > > /* RDMA DIM */ > > /* > * RDMA DIM profile: > diff --git a/lib/dim/net_dim.c b/lib/dim/net_dim.c > index d7e7028e9b19..d6aa09a979b3 100644 > --- a/lib/dim/net_dim.c > +++ b/lib/dim/net_dim.c > @@ -345,33 +345,33 @@ static bool net_dim_decision(struct dim_stats *curr_stats, struct dim *dim) > dim->prev_stats = *curr_stats; > > return dim->profile_ix != prev_ix; > } > > -void net_dim(struct dim *dim, struct dim_sample end_sample) > +void net_dim(struct dim *dim, const struct dim_sample *end_sample) > { > struct dim_stats curr_stats; > u16 nevents; > > switch (dim->state) { > case DIM_MEASURE_IN_PROGRESS: > nevents = BIT_GAP(BITS_PER_TYPE(u16), > - end_sample.event_ctr, > + end_sample->event_ctr, > dim->start_sample.event_ctr); > if (nevents < DIM_NEVENTS) > break; > - if (!dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats)) > + if (!dim_calc_stats(&dim->start_sample, end_sample, &curr_stats)) > break; > if (net_dim_decision(&curr_stats, dim)) { > dim->state = DIM_APPLY_NEW_PROFILE; > schedule_work(&dim->work); > break; > } > fallthrough; > case DIM_START_MEASURE: > - dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr, > - end_sample.byte_ctr, &dim->start_sample); > + dim_update_sample(end_sample->event_ctr, end_sample->pkt_ctr, > + end_sample->byte_ctr, &dim->start_sample); > dim->state = DIM_MEASURE_IN_PROGRESS; > break; > case DIM_APPLY_NEW_PROFILE: > break; > } > -- > 2.45.2 >
On 10/30/24 17:23, Caleb Sander Mateos wrote: > net_dim() is currently passed a struct dim_sample argument by value. > struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 > passes it on the stack. All callers have already initialized dim_sample > on the stack, so passing it by value requires pushing a duplicated copy > to the stack. Either witing to the stack and immediately reading it, or > perhaps dereferencing addresses relative to the stack pointer in a chain > of push instructions, seems to perform quite poorly. > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > 94% of which is attributed to the first push instruction to copy > dim_sample on the stack for the call to net_dim(): > // Call ktime_get() > 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> > // Pass the address of struct dim in %rdi > |4ead7: lea 0x3d0(%rbx),%rdi > // Set dim_sample.pkt_ctr > |4eade: mov %r13d,0x8(%rsp) > // Set dim_sample.byte_ctr > |4eae3: mov %r12d,0xc(%rsp) > // Set dim_sample.event_ctr > 0.15 |4eae8: mov %bp,0x10(%rsp) > // Duplicate dim_sample on the stack > 94.16 |4eaed: push 0x10(%rsp) > 2.79 |4eaf1: push 0x10(%rsp) > 0.07 |4eaf5: push %rax > // Call net_dim() > 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> > > To allow the caller to reuse the struct dim_sample already on the stack, > pass the struct dim_sample by reference to net_dim(). > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> #bcm{sysport,genet}.c Thanks!
On Thu, Oct 31, 2024 at 5:49 AM Louis Peens <louis.peens@corigine.com> wrote: > > On Wed, Oct 30, 2024 at 06:23:26PM -0600, Caleb Sander Mateos wrote: > > net_dim() is currently passed a struct dim_sample argument by value. > > struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 > > passes it on the stack. All callers have already initialized dim_sample > > on the stack, so passing it by value requires pushing a duplicated copy > > to the stack. Either witing to the stack and immediately reading it, or > > perhaps dereferencing addresses relative to the stack pointer in a chain > > of push instructions, seems to perform quite poorly. > > > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > > 94% of which is attributed to the first push instruction to copy > > dim_sample on the stack for the call to net_dim(): > > // Call ktime_get() > > 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> > > // Pass the address of struct dim in %rdi > > |4ead7: lea 0x3d0(%rbx),%rdi > > // Set dim_sample.pkt_ctr > > |4eade: mov %r13d,0x8(%rsp) > > // Set dim_sample.byte_ctr > > |4eae3: mov %r12d,0xc(%rsp) > > // Set dim_sample.event_ctr > > 0.15 |4eae8: mov %bp,0x10(%rsp) > > // Duplicate dim_sample on the stack > > 94.16 |4eaed: push 0x10(%rsp) > > 2.79 |4eaf1: push 0x10(%rsp) > > 0.07 |4eaf5: push %rax > > // Call net_dim() > > 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> > > > > To allow the caller to reuse the struct dim_sample already on the stack, > > pass the struct dim_sample by reference to net_dim(). > > > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> > > --- > > Documentation/networking/net_dim.rst | 2 +- > > drivers/net/ethernet/amazon/ena/ena_netdev.c | 2 +- > > drivers/net/ethernet/broadcom/bcmsysport.c | 2 +- > > drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++-- > > drivers/net/ethernet/broadcom/genet/bcmgenet.c | 2 +- > > drivers/net/ethernet/freescale/enetc/enetc.c | 2 +- > > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 4 ++-- > > drivers/net/ethernet/intel/ice/ice_txrx.c | 4 ++-- > > drivers/net/ethernet/intel/idpf/idpf_txrx.c | 4 ++-- > > drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 2 +- > > drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++-- > > drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c | 4 ++-- > > drivers/net/ethernet/netronome/nfp/nfd3/dp.c | 4 ++-- > > drivers/net/ethernet/netronome/nfp/nfdk/dp.c | 4 ++-- > > drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 2 +- > > drivers/net/virtio_net.c | 2 +- > > drivers/soc/fsl/dpio/dpio-service.c | 2 +- > > include/linux/dim.h | 2 +- > > lib/dim/net_dim.c | 10 +++++----- > > 19 files changed, 31 insertions(+), 31 deletions(-) > > > --- snip -- > > > diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > > index d215efc6cad0..f1c6c47564b1 100644 > > --- a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > > +++ b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > > @@ -1177,11 +1177,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > > pkts = r_vec->rx_pkts; > > bytes = r_vec->rx_bytes; > > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > > - net_dim(&r_vec->rx_dim, dim_sample); > > + net_dim(&r_vec->rx_dim, &dim_sample); > > } > > > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > > struct dim_sample dim_sample = {}; > > unsigned int start; > > @@ -1192,11 +1192,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > > pkts = r_vec->tx_pkts; > > bytes = r_vec->tx_bytes; > > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > > - net_dim(&r_vec->tx_dim, dim_sample); > > + net_dim(&r_vec->tx_dim, &dim_sample); > > } > > > > return pkts_polled; > > } > > > > diff --git a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > > index dae5af7d1845..ebeb6ab4465c 100644 > > --- a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > > +++ b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > > @@ -1287,11 +1287,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > > pkts = r_vec->rx_pkts; > > bytes = r_vec->rx_bytes; > > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > > - net_dim(&r_vec->rx_dim, dim_sample); > > + net_dim(&r_vec->rx_dim, &dim_sample); > > } > > > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > > struct dim_sample dim_sample = {}; > > unsigned int start; > > @@ -1302,11 +1302,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > > pkts = r_vec->tx_pkts; > > bytes = r_vec->tx_bytes; > > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > > - net_dim(&r_vec->tx_dim, dim_sample); > > + net_dim(&r_vec->tx_dim, &dim_sample); > > } > > > > return pkts_polled; > > } > --- snip --- > > Hi Caleb. Looks like a fair enough update to me in general, but I am not an > expert on 'dim'. For the corresponding nfp driver changes feel free to add: > > Signed-off-by: Louis Peens <louis.peens@corigine.com> Hi Louis, Thanks for the review. Did you mean "Reviewed-by"? If there was a change you were suggesting, I missed it. Best, Caleb
> -----Original Message----- > From: Caleb Sander Mateos <csander@purestorage.com> > Sent: Wednesday, October 30, 2024 5:23 PM > > net_dim() is currently passed a struct dim_sample argument by value. > struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 passes it > on the stack. All callers have already initialized dim_sample on the stack, so > passing it by value requires pushing a duplicated copy to the stack. Either > witing to the stack and immediately reading it, or perhaps dereferencing > addresses relative to the stack pointer in a chain of push instructions, seems > to perform quite poorly. > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > 94% of which is attributed to the first push instruction to copy dim_sample on > the stack for the call to net_dim(): > // Call ktime_get() > 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> > // Pass the address of struct dim in %rdi > |4ead7: lea 0x3d0(%rbx),%rdi > // Set dim_sample.pkt_ctr > |4eade: mov %r13d,0x8(%rsp) > // Set dim_sample.byte_ctr > |4eae3: mov %r12d,0xc(%rsp) > // Set dim_sample.event_ctr > 0.15 |4eae8: mov %bp,0x10(%rsp) > // Duplicate dim_sample on the stack > 94.16 |4eaed: push 0x10(%rsp) > 2.79 |4eaf1: push 0x10(%rsp) > 0.07 |4eaf5: push %rax > // Call net_dim() > 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> > > To allow the caller to reuse the struct dim_sample already on the stack, pass > the struct dim_sample by reference to net_dim(). > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> > --- Thank you for this patch. For the ENA part: Reviewed-by: Arthur Kiyanovski <akiyano@amazon.com> Thanks, Arthur
On Thu, Oct 31, 2024 at 10:19:55AM -0700, Caleb Sander wrote: > [Some people who received this message don't often get email from csander@purestorage.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > > On Thu, Oct 31, 2024 at 5:49 AM Louis Peens <louis.peens@corigine.com> wrote: > > > > On Wed, Oct 30, 2024 at 06:23:26PM -0600, Caleb Sander Mateos wrote: > > > net_dim() is currently passed a struct dim_sample argument by value. > > > struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 > > > passes it on the stack. All callers have already initialized dim_sample > > > on the stack, so passing it by value requires pushing a duplicated copy > > > to the stack. Either witing to the stack and immediately reading it, or > > > perhaps dereferencing addresses relative to the stack pointer in a chain > > > of push instructions, seems to perform quite poorly. > > > > > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > > > 94% of which is attributed to the first push instruction to copy > > > dim_sample on the stack for the call to net_dim(): > > > // Call ktime_get() > > > 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> > > > // Pass the address of struct dim in %rdi > > > |4ead7: lea 0x3d0(%rbx),%rdi > > > // Set dim_sample.pkt_ctr > > > |4eade: mov %r13d,0x8(%rsp) > > > // Set dim_sample.byte_ctr > > > |4eae3: mov %r12d,0xc(%rsp) > > > // Set dim_sample.event_ctr > > > 0.15 |4eae8: mov %bp,0x10(%rsp) > > > // Duplicate dim_sample on the stack > > > 94.16 |4eaed: push 0x10(%rsp) > > > 2.79 |4eaf1: push 0x10(%rsp) > > > 0.07 |4eaf5: push %rax > > > // Call net_dim() > > > 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> > > > > > > To allow the caller to reuse the struct dim_sample already on the stack, > > > pass the struct dim_sample by reference to net_dim(). > > > > > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> > > > --- > > > Documentation/networking/net_dim.rst | 2 +- > > > drivers/net/ethernet/amazon/ena/ena_netdev.c | 2 +- > > > drivers/net/ethernet/broadcom/bcmsysport.c | 2 +- > > > drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++-- > > > drivers/net/ethernet/broadcom/genet/bcmgenet.c | 2 +- > > > drivers/net/ethernet/freescale/enetc/enetc.c | 2 +- > > > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 4 ++-- > > > drivers/net/ethernet/intel/ice/ice_txrx.c | 4 ++-- > > > drivers/net/ethernet/intel/idpf/idpf_txrx.c | 4 ++-- > > > drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 2 +- > > > drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++-- > > > drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c | 4 ++-- > > > drivers/net/ethernet/netronome/nfp/nfd3/dp.c | 4 ++-- > > > drivers/net/ethernet/netronome/nfp/nfdk/dp.c | 4 ++-- > > > drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 2 +- > > > drivers/net/virtio_net.c | 2 +- > > > drivers/soc/fsl/dpio/dpio-service.c | 2 +- > > > include/linux/dim.h | 2 +- > > > lib/dim/net_dim.c | 10 +++++----- > > > 19 files changed, 31 insertions(+), 31 deletions(-) > > > > > --- snip -- > > > > > diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > > > index d215efc6cad0..f1c6c47564b1 100644 > > > --- a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > > > +++ b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > > > @@ -1177,11 +1177,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > > > pkts = r_vec->rx_pkts; > > > bytes = r_vec->rx_bytes; > > > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > > > > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > > > - net_dim(&r_vec->rx_dim, dim_sample); > > > + net_dim(&r_vec->rx_dim, &dim_sample); > > > } > > > > > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > > > struct dim_sample dim_sample = {}; > > > unsigned int start; > > > @@ -1192,11 +1192,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > > > pkts = r_vec->tx_pkts; > > > bytes = r_vec->tx_bytes; > > > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > > > > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > > > - net_dim(&r_vec->tx_dim, dim_sample); > > > + net_dim(&r_vec->tx_dim, &dim_sample); > > > } > > > > > > return pkts_polled; > > > } > > > > > > diff --git a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > > > index dae5af7d1845..ebeb6ab4465c 100644 > > > --- a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > > > +++ b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > > > @@ -1287,11 +1287,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > > > pkts = r_vec->rx_pkts; > > > bytes = r_vec->rx_bytes; > > > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > > > > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > > > - net_dim(&r_vec->rx_dim, dim_sample); > > > + net_dim(&r_vec->rx_dim, &dim_sample); > > > } > > > > > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > > > struct dim_sample dim_sample = {}; > > > unsigned int start; > > > @@ -1302,11 +1302,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > > > pkts = r_vec->tx_pkts; > > > bytes = r_vec->tx_bytes; > > > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > > > > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > > > - net_dim(&r_vec->tx_dim, dim_sample); > > > + net_dim(&r_vec->tx_dim, &dim_sample); > > > } > > > > > > return pkts_polled; > > > } > > --- snip --- > > > > Hi Caleb. Looks like a fair enough update to me in general, but I am not an > > expert on 'dim'. For the corresponding nfp driver changes feel free to add: > > > > Signed-off-by: Louis Peens <louis.peens@corigine.com> > > Hi Louis, > Thanks for the review. Did you mean "Reviewed-by"? If there was a > change you were suggesting, I missed it. Hi - sorry, I do still manage to mix up when to use signed-off-by and reviewed-by. I did not suggest any changes no, and since the main focus of the patch is not the nfp driver I can see in hindsight that Reviewed-by: may make more sense. So updated: Reviewed-by: Louis Peens <louis.peens@corigine.com> > > Best, > Caleb
On Fri, Nov 01, 2024 at 10:54:47AM +0200, Louis Peens wrote: > Hi - sorry, I do still manage to mix up when to use signed-off-by and > reviewed-by. You use Signed-off-by when you submit a patch and Reviewed-by when you review it.
On Wed, 30 Oct 2024 18:23:26 -0600 Caleb Sander Mateos wrote: > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > 94% of which is attributed to the first push instruction to copy > dim_sample on the stack for the call to net_dim(): Change itself looks fine, so we can apply, but this seems surprising. Are you sure this is not just some measurement problem? Do you see 3% higher PPS with this change applied?
On Sun, Nov 3, 2024 at 12:21 PM Jakub Kicinski <kuba@kernel.org> wrote: > > On Wed, 30 Oct 2024 18:23:26 -0600 Caleb Sander Mateos wrote: > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > > 94% of which is attributed to the first push instruction to copy > > dim_sample on the stack for the call to net_dim(): > > Change itself looks fine, so we can apply, but this seems surprising. > Are you sure this is not just some measurement problem? > Do you see 3% higher PPS with this change applied? Agreed, this bottleneck surprised me too. But the CPU profiles clearly point to this push instruction in mlx5e_handle_rx_dim() being very hot. My best explanation is that the 2- and 4-byte stores followed immediately by 8-byte loads from the same addresses cannot be pipelined effectively. The loads must wait for the stores to complete before reading back the values they wrote. Ideally the compiler would recognize that the struct dim_sample local variable is only used to pass to net_dim() and avoid duplicating it. I guess passing large structs by value in C is not very common, so there probably isn't as much effort put into optimizing it. With the patches applied, the CPU time spent in mlx5e_handle_rx_dim() (excluding children) drops from 3.14% to 0.08%. Unfortunately, there are other bottlenecks in the system and 1% variation in the throughput is typical, so the patches don't translate into a clear 3% increase in throughput. Best, Caleb
On Wed, 30 Oct 2024 18:23:26 -0600, Caleb Sander Mateos <csander@purestorage.com> wrote: > net_dim() is currently passed a struct dim_sample argument by value. > struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 > passes it on the stack. All callers have already initialized dim_sample > on the stack, so passing it by value requires pushing a duplicated copy > to the stack. Either witing to the stack and immediately reading it, or > perhaps dereferencing addresses relative to the stack pointer in a chain > of push instructions, seems to perform quite poorly. > > In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, > 94% of which is attributed to the first push instruction to copy > dim_sample on the stack for the call to net_dim(): > // Call ktime_get() > 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> > // Pass the address of struct dim in %rdi > |4ead7: lea 0x3d0(%rbx),%rdi > // Set dim_sample.pkt_ctr > |4eade: mov %r13d,0x8(%rsp) > // Set dim_sample.byte_ctr > |4eae3: mov %r12d,0xc(%rsp) > // Set dim_sample.event_ctr > 0.15 |4eae8: mov %bp,0x10(%rsp) > // Duplicate dim_sample on the stack > 94.16 |4eaed: push 0x10(%rsp) > 2.79 |4eaf1: push 0x10(%rsp) > 0.07 |4eaf5: push %rax > // Call net_dim() > 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> > > To allow the caller to reuse the struct dim_sample already on the stack, > pass the struct dim_sample by reference to net_dim(). > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> For virtio-net: Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> > --- > Documentation/networking/net_dim.rst | 2 +- > drivers/net/ethernet/amazon/ena/ena_netdev.c | 2 +- > drivers/net/ethernet/broadcom/bcmsysport.c | 2 +- > drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++-- > drivers/net/ethernet/broadcom/genet/bcmgenet.c | 2 +- > drivers/net/ethernet/freescale/enetc/enetc.c | 2 +- > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 4 ++-- > drivers/net/ethernet/intel/ice/ice_txrx.c | 4 ++-- > drivers/net/ethernet/intel/idpf/idpf_txrx.c | 4 ++-- > drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 2 +- > drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++-- > drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c | 4 ++-- > drivers/net/ethernet/netronome/nfp/nfd3/dp.c | 4 ++-- > drivers/net/ethernet/netronome/nfp/nfdk/dp.c | 4 ++-- > drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 2 +- > drivers/net/virtio_net.c | 2 +- > drivers/soc/fsl/dpio/dpio-service.c | 2 +- > include/linux/dim.h | 2 +- > lib/dim/net_dim.c | 10 +++++----- > 19 files changed, 31 insertions(+), 31 deletions(-) > > diff --git a/Documentation/networking/net_dim.rst b/Documentation/networking/net_dim.rst > index 8908fd7b0a8d..4377998e6826 100644 > --- a/Documentation/networking/net_dim.rst > +++ b/Documentation/networking/net_dim.rst > @@ -154,11 +154,11 @@ usage is not complete but it should make the outline of the usage clear. > dim_update_sample(my_entity->events, > my_entity->packets, > my_entity->bytes, > &dim_sample); > /* Call net DIM */ > - net_dim(&my_entity->dim, dim_sample); > + net_dim(&my_entity->dim, &dim_sample); > ... > } > > /* My entity's initialization function (my_entity was already allocated) */ > int my_driver_init_my_entity(struct my_driver_entity *my_entity, ...) > diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c > index 96df20854eb9..63c8a2328142 100644 > --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c > +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c > @@ -1381,11 +1381,11 @@ static void ena_adjust_adaptive_rx_intr_moderation(struct ena_napi *ena_napi) > dim_update_sample(rx_ring->non_empty_napi_events, > rx_ring->rx_stats.cnt, > rx_ring->rx_stats.bytes, > &dim_sample); > > - net_dim(&ena_napi->dim, dim_sample); > + net_dim(&ena_napi->dim, &dim_sample); > > rx_ring->per_napi_packets = 0; > } > > void ena_unmask_interrupt(struct ena_ring *tx_ring, > diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c > index caff6e87a488..031e9e0cca53 100644 > --- a/drivers/net/ethernet/broadcom/bcmsysport.c > +++ b/drivers/net/ethernet/broadcom/bcmsysport.c > @@ -1027,11 +1027,11 @@ static int bcm_sysport_poll(struct napi_struct *napi, int budget) > } > > if (priv->dim.use_dim) { > dim_update_sample(priv->dim.event_ctr, priv->dim.packets, > priv->dim.bytes, &dim_sample); > - net_dim(&priv->dim.dim, dim_sample); > + net_dim(&priv->dim.dim, &dim_sample); > } > > return work_done; > } > > diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c > index 6dd6541d8619..ca42b81133d7 100644 > --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c > +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c > @@ -3100,11 +3100,11 @@ static int bnxt_poll(struct napi_struct *napi, int budget) > > dim_update_sample(cpr->event_ctr, > cpr->rx_packets, > cpr->rx_bytes, > &dim_sample); > - net_dim(&cpr->dim, dim_sample); > + net_dim(&cpr->dim, &dim_sample); > } > return work_done; > } > > static int __bnxt_poll_cqs(struct bnxt *bp, struct bnxt_napi *bnapi, int budget) > @@ -3231,11 +3231,11 @@ static int bnxt_poll_p5(struct napi_struct *napi, int budget) > > dim_update_sample(cpr->event_ctr, > cpr_rx->rx_packets, > cpr_rx->rx_bytes, > &dim_sample); > - net_dim(&cpr->dim, dim_sample); > + net_dim(&cpr->dim, &dim_sample); > } > return work_done; > } > > static void bnxt_free_tx_skbs(struct bnxt *bp) > diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c > index 10966ab15373..53a949eb9180 100644 > --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c > +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c > @@ -2403,11 +2403,11 @@ static int bcmgenet_rx_poll(struct napi_struct *napi, int budget) > } > > if (ring->dim.use_dim) { > dim_update_sample(ring->dim.event_ctr, ring->dim.packets, > ring->dim.bytes, &dim_sample); > - net_dim(&ring->dim.dim, dim_sample); > + net_dim(&ring->dim.dim, &dim_sample); > } > > return work_done; > } > > diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c > index c09370eab319..05dedea6185a 100644 > --- a/drivers/net/ethernet/freescale/enetc/enetc.c > +++ b/drivers/net/ethernet/freescale/enetc/enetc.c > @@ -716,11 +716,11 @@ static void enetc_rx_net_dim(struct enetc_int_vector *v) > > dim_update_sample(v->comp_cnt, > v->rx_ring.stats.packets, > v->rx_ring.stats.bytes, > &dim_sample); > - net_dim(&v->rx_dim, dim_sample); > + net_dim(&v->rx_dim, &dim_sample); > } > > static int enetc_bd_ready_count(struct enetc_bdr *tx_ring, int ci) > { > int pi = enetc_rd_reg_hot(tx_ring->tcir) & ENETC_TBCIR_IDX_MASK; > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > index 4cbc4d069a1f..43377a7b2426 100644 > --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > @@ -4446,11 +4446,11 @@ static void hns3_update_rx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) > if (!rx_group->coal.adapt_enable) > return; > > dim_update_sample(tqp_vector->event_cnt, rx_group->total_packets, > rx_group->total_bytes, &sample); > - net_dim(&rx_group->dim, sample); > + net_dim(&rx_group->dim, &sample); > } > > static void hns3_update_tx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) > { > struct hns3_enet_ring_group *tx_group = &tqp_vector->tx_group; > @@ -4459,11 +4459,11 @@ static void hns3_update_tx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) > if (!tx_group->coal.adapt_enable) > return; > > dim_update_sample(tqp_vector->event_cnt, tx_group->total_packets, > tx_group->total_bytes, &sample); > - net_dim(&tx_group->dim, sample); > + net_dim(&tx_group->dim, &sample); > } > > static int hns3_nic_common_poll(struct napi_struct *napi, int budget) > { > struct hns3_nic_priv *priv = netdev_priv(napi->dev); > diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c > index 8208055d6e7f..5d2d7736fd5f 100644 > --- a/drivers/net/ethernet/intel/ice/ice_txrx.c > +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c > @@ -1350,18 +1350,18 @@ static void ice_net_dim(struct ice_q_vector *q_vector) > > if (ITR_IS_DYNAMIC(tx)) { > struct dim_sample dim_sample; > > __ice_update_sample(q_vector, tx, &dim_sample, true); > - net_dim(&tx->dim, dim_sample); > + net_dim(&tx->dim, &dim_sample); > } > > if (ITR_IS_DYNAMIC(rx)) { > struct dim_sample dim_sample; > > __ice_update_sample(q_vector, rx, &dim_sample, false); > - net_dim(&rx->dim, dim_sample); > + net_dim(&rx->dim, &dim_sample); > } > } > > /** > * ice_buildreg_itr - build value for writing to the GLINT_DYN_CTL register > diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c > index d4e6f0e10487..da2a5becf62f 100644 > --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c > +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c > @@ -3677,11 +3677,11 @@ static void idpf_net_dim(struct idpf_q_vector *q_vector) > } while (u64_stats_fetch_retry(&txq->stats_sync, start)); > } > > idpf_update_dim_sample(q_vector, &dim_sample, &q_vector->tx_dim, > packets, bytes); > - net_dim(&q_vector->tx_dim, dim_sample); > + net_dim(&q_vector->tx_dim, &dim_sample); > > check_rx_itr: > if (!IDPF_ITR_IS_DYNAMIC(q_vector->rx_intr_mode)) > return; > > @@ -3696,11 +3696,11 @@ static void idpf_net_dim(struct idpf_q_vector *q_vector) > } while (u64_stats_fetch_retry(&rxq->stats_sync, start)); > } > > idpf_update_dim_sample(q_vector, &dim_sample, &q_vector->rx_dim, > packets, bytes); > - net_dim(&q_vector->rx_dim, dim_sample); > + net_dim(&q_vector->rx_dim, &dim_sample); > } > > /** > * idpf_vport_intr_update_itr_ena_irq - Update itr and re-enable MSIX interrupt > * @q_vector: q_vector for which itr is being updated and interrupt enabled > diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c > index 933e18ba2fb2..7aaf32e9aa95 100644 > --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c > +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c > @@ -525,11 +525,11 @@ static void otx2_adjust_adaptive_coalese(struct otx2_nic *pfvf, struct otx2_cq_p > > dim_update_sample(pfvf->napi_events, > rx_frames + tx_frames, > rx_bytes + tx_bytes, > &dim_sample); > - net_dim(&cq_poll->dim, dim_sample); > + net_dim(&cq_poll->dim, &dim_sample); > } > > int otx2_napi_handler(struct napi_struct *napi, int budget) > { > struct otx2_cq_queue *rx_cq = NULL; > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c > index f01ceee5f02d..53485142938c 100644 > --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c > +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c > @@ -2225,11 +2225,11 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget, > > eth->rx_packets += done; > eth->rx_bytes += bytes; > dim_update_sample(eth->rx_events, eth->rx_packets, eth->rx_bytes, > &dim_sample); > - net_dim(ð->rx_dim, dim_sample); > + net_dim(ð->rx_dim, &dim_sample); > > if (xdp_flush) > xdp_do_flush(); > > return done; > @@ -2375,11 +2375,11 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget) > if (state.txq) > netdev_tx_completed_queue(state.txq, state.done, state.bytes); > > dim_update_sample(eth->tx_events, eth->tx_packets, eth->tx_bytes, > &dim_sample); > - net_dim(ð->tx_dim, dim_sample); > + net_dim(ð->tx_dim, &dim_sample); > > if (mtk_queue_stopped(eth) && > (atomic_read(&ring->free_count) > ring->thresh)) > mtk_wake_queue(eth); > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c > index 5873fde65c2e..417098f0b2bb 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c > @@ -53,11 +53,11 @@ static void mlx5e_handle_tx_dim(struct mlx5e_txqsq *sq) > > if (unlikely(!test_bit(MLX5E_SQ_STATE_DIM, &sq->state))) > return; > > dim_update_sample(sq->cq.event_ctr, stats->packets, stats->bytes, &dim_sample); > - net_dim(sq->dim, dim_sample); > + net_dim(sq->dim, &dim_sample); > } > > static void mlx5e_handle_rx_dim(struct mlx5e_rq *rq) > { > struct mlx5e_rq_stats *stats = rq->stats; > @@ -65,11 +65,11 @@ static void mlx5e_handle_rx_dim(struct mlx5e_rq *rq) > > if (unlikely(!test_bit(MLX5E_RQ_STATE_DIM, &rq->state))) > return; > > dim_update_sample(rq->cq.event_ctr, stats->packets, stats->bytes, &dim_sample); > - net_dim(rq->dim, dim_sample); > + net_dim(rq->dim, &dim_sample); > } > > void mlx5e_trigger_irq(struct mlx5e_icosq *sq) > { > struct mlx5_wq_cyc *wq = &sq->wq; > diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > index d215efc6cad0..f1c6c47564b1 100644 > --- a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > +++ b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c > @@ -1177,11 +1177,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > pkts = r_vec->rx_pkts; > bytes = r_vec->rx_bytes; > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->rx_dim, dim_sample); > + net_dim(&r_vec->rx_dim, &dim_sample); > } > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > struct dim_sample dim_sample = {}; > unsigned int start; > @@ -1192,11 +1192,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) > pkts = r_vec->tx_pkts; > bytes = r_vec->tx_bytes; > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->tx_dim, dim_sample); > + net_dim(&r_vec->tx_dim, &dim_sample); > } > > return pkts_polled; > } > > diff --git a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > index dae5af7d1845..ebeb6ab4465c 100644 > --- a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > +++ b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c > @@ -1287,11 +1287,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > pkts = r_vec->rx_pkts; > bytes = r_vec->rx_bytes; > } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->rx_dim, dim_sample); > + net_dim(&r_vec->rx_dim, &dim_sample); > } > > if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { > struct dim_sample dim_sample = {}; > unsigned int start; > @@ -1302,11 +1302,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) > pkts = r_vec->tx_pkts; > bytes = r_vec->tx_bytes; > } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); > > dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); > - net_dim(&r_vec->tx_dim, dim_sample); > + net_dim(&r_vec->tx_dim, &dim_sample); > } > > return pkts_polled; > } > > diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c > index 0eeda7e502db..2ac59564ded1 100644 > --- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c > +++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c > @@ -926,11 +926,11 @@ static void ionic_dim_update(struct ionic_qcq *qcq, int napi_mode) > } > > dim_update_sample(qcq->cq.bound_intr->rearm_count, > pkts, bytes, &dim_sample); > > - net_dim(&qcq->dim, dim_sample); > + net_dim(&qcq->dim, &dim_sample); > } > > int ionic_tx_napi(struct napi_struct *napi, int budget) > { > struct ionic_qcq *qcq = napi_to_qcq(napi); > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 792e9eadbfc3..869586c17ffd 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -2802,11 +2802,11 @@ static void virtnet_rx_dim_update(struct virtnet_info *vi, struct receive_queue > dim_update_sample(rq->calls, > u64_stats_read(&rq->stats.packets), > u64_stats_read(&rq->stats.bytes), > &cur_sample); > > - net_dim(&rq->dim, cur_sample); > + net_dim(&rq->dim, &cur_sample); > rq->packets_in_napi = 0; > } > > static int virtnet_poll(struct napi_struct *napi, int budget) > { > diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c > index b811446e0fa5..0b60ed16297c 100644 > --- a/drivers/soc/fsl/dpio/dpio-service.c > +++ b/drivers/soc/fsl/dpio/dpio-service.c > @@ -889,10 +889,10 @@ void dpaa2_io_update_net_dim(struct dpaa2_io *d, __u64 frames, __u64 bytes) > > d->bytes += bytes; > d->frames += frames; > > dim_update_sample(d->event_ctr, d->frames, d->bytes, &dim_sample); > - net_dim(&d->rx_dim, dim_sample); > + net_dim(&d->rx_dim, &dim_sample); > > spin_unlock(&d->dim_lock); > } > EXPORT_SYMBOL(dpaa2_io_update_net_dim); > diff --git a/include/linux/dim.h b/include/linux/dim.h > index 84579a50ae7f..06543fd40fcc 100644 > --- a/include/linux/dim.h > +++ b/include/linux/dim.h > @@ -423,11 +423,11 @@ struct dim_cq_moder net_dim_get_def_tx_moderation(u8 cq_period_mode); > * > * Called by the consumer. > * This is the main logic of the algorithm, where data is processed in order > * to decide on next required action. > */ > -void net_dim(struct dim *dim, struct dim_sample end_sample); > +void net_dim(struct dim *dim, const struct dim_sample *end_sample); > > /* RDMA DIM */ > > /* > * RDMA DIM profile: > diff --git a/lib/dim/net_dim.c b/lib/dim/net_dim.c > index d7e7028e9b19..d6aa09a979b3 100644 > --- a/lib/dim/net_dim.c > +++ b/lib/dim/net_dim.c > @@ -345,33 +345,33 @@ static bool net_dim_decision(struct dim_stats *curr_stats, struct dim *dim) > dim->prev_stats = *curr_stats; > > return dim->profile_ix != prev_ix; > } > > -void net_dim(struct dim *dim, struct dim_sample end_sample) > +void net_dim(struct dim *dim, const struct dim_sample *end_sample) > { > struct dim_stats curr_stats; > u16 nevents; > > switch (dim->state) { > case DIM_MEASURE_IN_PROGRESS: > nevents = BIT_GAP(BITS_PER_TYPE(u16), > - end_sample.event_ctr, > + end_sample->event_ctr, > dim->start_sample.event_ctr); > if (nevents < DIM_NEVENTS) > break; > - if (!dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats)) > + if (!dim_calc_stats(&dim->start_sample, end_sample, &curr_stats)) > break; > if (net_dim_decision(&curr_stats, dim)) { > dim->state = DIM_APPLY_NEW_PROFILE; > schedule_work(&dim->work); > break; > } > fallthrough; > case DIM_START_MEASURE: > - dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr, > - end_sample.byte_ctr, &dim->start_sample); > + dim_update_sample(end_sample->event_ctr, end_sample->pkt_ctr, > + end_sample->byte_ctr, &dim->start_sample); > dim->state = DIM_MEASURE_IN_PROGRESS; > break; > case DIM_APPLY_NEW_PROFILE: > break; > } > -- > 2.45.2 >
diff --git a/Documentation/networking/net_dim.rst b/Documentation/networking/net_dim.rst index 8908fd7b0a8d..4377998e6826 100644 --- a/Documentation/networking/net_dim.rst +++ b/Documentation/networking/net_dim.rst @@ -154,11 +154,11 @@ usage is not complete but it should make the outline of the usage clear. dim_update_sample(my_entity->events, my_entity->packets, my_entity->bytes, &dim_sample); /* Call net DIM */ - net_dim(&my_entity->dim, dim_sample); + net_dim(&my_entity->dim, &dim_sample); ... } /* My entity's initialization function (my_entity was already allocated) */ int my_driver_init_my_entity(struct my_driver_entity *my_entity, ...) diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index 96df20854eb9..63c8a2328142 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -1381,11 +1381,11 @@ static void ena_adjust_adaptive_rx_intr_moderation(struct ena_napi *ena_napi) dim_update_sample(rx_ring->non_empty_napi_events, rx_ring->rx_stats.cnt, rx_ring->rx_stats.bytes, &dim_sample); - net_dim(&ena_napi->dim, dim_sample); + net_dim(&ena_napi->dim, &dim_sample); rx_ring->per_napi_packets = 0; } void ena_unmask_interrupt(struct ena_ring *tx_ring, diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c index caff6e87a488..031e9e0cca53 100644 --- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -1027,11 +1027,11 @@ static int bcm_sysport_poll(struct napi_struct *napi, int budget) } if (priv->dim.use_dim) { dim_update_sample(priv->dim.event_ctr, priv->dim.packets, priv->dim.bytes, &dim_sample); - net_dim(&priv->dim.dim, dim_sample); + net_dim(&priv->dim.dim, &dim_sample); } return work_done; } diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 6dd6541d8619..ca42b81133d7 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -3100,11 +3100,11 @@ static int bnxt_poll(struct napi_struct *napi, int budget) dim_update_sample(cpr->event_ctr, cpr->rx_packets, cpr->rx_bytes, &dim_sample); - net_dim(&cpr->dim, dim_sample); + net_dim(&cpr->dim, &dim_sample); } return work_done; } static int __bnxt_poll_cqs(struct bnxt *bp, struct bnxt_napi *bnapi, int budget) @@ -3231,11 +3231,11 @@ static int bnxt_poll_p5(struct napi_struct *napi, int budget) dim_update_sample(cpr->event_ctr, cpr_rx->rx_packets, cpr_rx->rx_bytes, &dim_sample); - net_dim(&cpr->dim, dim_sample); + net_dim(&cpr->dim, &dim_sample); } return work_done; } static void bnxt_free_tx_skbs(struct bnxt *bp) diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index 10966ab15373..53a949eb9180 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -2403,11 +2403,11 @@ static int bcmgenet_rx_poll(struct napi_struct *napi, int budget) } if (ring->dim.use_dim) { dim_update_sample(ring->dim.event_ctr, ring->dim.packets, ring->dim.bytes, &dim_sample); - net_dim(&ring->dim.dim, dim_sample); + net_dim(&ring->dim.dim, &dim_sample); } return work_done; } diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index c09370eab319..05dedea6185a 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -716,11 +716,11 @@ static void enetc_rx_net_dim(struct enetc_int_vector *v) dim_update_sample(v->comp_cnt, v->rx_ring.stats.packets, v->rx_ring.stats.bytes, &dim_sample); - net_dim(&v->rx_dim, dim_sample); + net_dim(&v->rx_dim, &dim_sample); } static int enetc_bd_ready_count(struct enetc_bdr *tx_ring, int ci) { int pi = enetc_rd_reg_hot(tx_ring->tcir) & ENETC_TBCIR_IDX_MASK; diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index 4cbc4d069a1f..43377a7b2426 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -4446,11 +4446,11 @@ static void hns3_update_rx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) if (!rx_group->coal.adapt_enable) return; dim_update_sample(tqp_vector->event_cnt, rx_group->total_packets, rx_group->total_bytes, &sample); - net_dim(&rx_group->dim, sample); + net_dim(&rx_group->dim, &sample); } static void hns3_update_tx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) { struct hns3_enet_ring_group *tx_group = &tqp_vector->tx_group; @@ -4459,11 +4459,11 @@ static void hns3_update_tx_int_coalesce(struct hns3_enet_tqp_vector *tqp_vector) if (!tx_group->coal.adapt_enable) return; dim_update_sample(tqp_vector->event_cnt, tx_group->total_packets, tx_group->total_bytes, &sample); - net_dim(&tx_group->dim, sample); + net_dim(&tx_group->dim, &sample); } static int hns3_nic_common_poll(struct napi_struct *napi, int budget) { struct hns3_nic_priv *priv = netdev_priv(napi->dev); diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index 8208055d6e7f..5d2d7736fd5f 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -1350,18 +1350,18 @@ static void ice_net_dim(struct ice_q_vector *q_vector) if (ITR_IS_DYNAMIC(tx)) { struct dim_sample dim_sample; __ice_update_sample(q_vector, tx, &dim_sample, true); - net_dim(&tx->dim, dim_sample); + net_dim(&tx->dim, &dim_sample); } if (ITR_IS_DYNAMIC(rx)) { struct dim_sample dim_sample; __ice_update_sample(q_vector, rx, &dim_sample, false); - net_dim(&rx->dim, dim_sample); + net_dim(&rx->dim, &dim_sample); } } /** * ice_buildreg_itr - build value for writing to the GLINT_DYN_CTL register diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c index d4e6f0e10487..da2a5becf62f 100644 --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c @@ -3677,11 +3677,11 @@ static void idpf_net_dim(struct idpf_q_vector *q_vector) } while (u64_stats_fetch_retry(&txq->stats_sync, start)); } idpf_update_dim_sample(q_vector, &dim_sample, &q_vector->tx_dim, packets, bytes); - net_dim(&q_vector->tx_dim, dim_sample); + net_dim(&q_vector->tx_dim, &dim_sample); check_rx_itr: if (!IDPF_ITR_IS_DYNAMIC(q_vector->rx_intr_mode)) return; @@ -3696,11 +3696,11 @@ static void idpf_net_dim(struct idpf_q_vector *q_vector) } while (u64_stats_fetch_retry(&rxq->stats_sync, start)); } idpf_update_dim_sample(q_vector, &dim_sample, &q_vector->rx_dim, packets, bytes); - net_dim(&q_vector->rx_dim, dim_sample); + net_dim(&q_vector->rx_dim, &dim_sample); } /** * idpf_vport_intr_update_itr_ena_irq - Update itr and re-enable MSIX interrupt * @q_vector: q_vector for which itr is being updated and interrupt enabled diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c index 933e18ba2fb2..7aaf32e9aa95 100644 --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c @@ -525,11 +525,11 @@ static void otx2_adjust_adaptive_coalese(struct otx2_nic *pfvf, struct otx2_cq_p dim_update_sample(pfvf->napi_events, rx_frames + tx_frames, rx_bytes + tx_bytes, &dim_sample); - net_dim(&cq_poll->dim, dim_sample); + net_dim(&cq_poll->dim, &dim_sample); } int otx2_napi_handler(struct napi_struct *napi, int budget) { struct otx2_cq_queue *rx_cq = NULL; diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c index f01ceee5f02d..53485142938c 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -2225,11 +2225,11 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget, eth->rx_packets += done; eth->rx_bytes += bytes; dim_update_sample(eth->rx_events, eth->rx_packets, eth->rx_bytes, &dim_sample); - net_dim(ð->rx_dim, dim_sample); + net_dim(ð->rx_dim, &dim_sample); if (xdp_flush) xdp_do_flush(); return done; @@ -2375,11 +2375,11 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget) if (state.txq) netdev_tx_completed_queue(state.txq, state.done, state.bytes); dim_update_sample(eth->tx_events, eth->tx_packets, eth->tx_bytes, &dim_sample); - net_dim(ð->tx_dim, dim_sample); + net_dim(ð->tx_dim, &dim_sample); if (mtk_queue_stopped(eth) && (atomic_read(&ring->free_count) > ring->thresh)) mtk_wake_queue(eth); diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c index 5873fde65c2e..417098f0b2bb 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c @@ -53,11 +53,11 @@ static void mlx5e_handle_tx_dim(struct mlx5e_txqsq *sq) if (unlikely(!test_bit(MLX5E_SQ_STATE_DIM, &sq->state))) return; dim_update_sample(sq->cq.event_ctr, stats->packets, stats->bytes, &dim_sample); - net_dim(sq->dim, dim_sample); + net_dim(sq->dim, &dim_sample); } static void mlx5e_handle_rx_dim(struct mlx5e_rq *rq) { struct mlx5e_rq_stats *stats = rq->stats; @@ -65,11 +65,11 @@ static void mlx5e_handle_rx_dim(struct mlx5e_rq *rq) if (unlikely(!test_bit(MLX5E_RQ_STATE_DIM, &rq->state))) return; dim_update_sample(rq->cq.event_ctr, stats->packets, stats->bytes, &dim_sample); - net_dim(rq->dim, dim_sample); + net_dim(rq->dim, &dim_sample); } void mlx5e_trigger_irq(struct mlx5e_icosq *sq) { struct mlx5_wq_cyc *wq = &sq->wq; diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c index d215efc6cad0..f1c6c47564b1 100644 --- a/drivers/net/ethernet/netronome/nfp/nfd3/dp.c +++ b/drivers/net/ethernet/netronome/nfp/nfd3/dp.c @@ -1177,11 +1177,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) pkts = r_vec->rx_pkts; bytes = r_vec->rx_bytes; } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); - net_dim(&r_vec->rx_dim, dim_sample); + net_dim(&r_vec->rx_dim, &dim_sample); } if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { struct dim_sample dim_sample = {}; unsigned int start; @@ -1192,11 +1192,11 @@ int nfp_nfd3_poll(struct napi_struct *napi, int budget) pkts = r_vec->tx_pkts; bytes = r_vec->tx_bytes; } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); - net_dim(&r_vec->tx_dim, dim_sample); + net_dim(&r_vec->tx_dim, &dim_sample); } return pkts_polled; } diff --git a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c index dae5af7d1845..ebeb6ab4465c 100644 --- a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c +++ b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c @@ -1287,11 +1287,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) pkts = r_vec->rx_pkts; bytes = r_vec->rx_bytes; } while (u64_stats_fetch_retry(&r_vec->rx_sync, start)); dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); - net_dim(&r_vec->rx_dim, dim_sample); + net_dim(&r_vec->rx_dim, &dim_sample); } if (r_vec->nfp_net->tx_coalesce_adapt_on && r_vec->tx_ring) { struct dim_sample dim_sample = {}; unsigned int start; @@ -1302,11 +1302,11 @@ int nfp_nfdk_poll(struct napi_struct *napi, int budget) pkts = r_vec->tx_pkts; bytes = r_vec->tx_bytes; } while (u64_stats_fetch_retry(&r_vec->tx_sync, start)); dim_update_sample(r_vec->event_ctr, pkts, bytes, &dim_sample); - net_dim(&r_vec->tx_dim, dim_sample); + net_dim(&r_vec->tx_dim, &dim_sample); } return pkts_polled; } diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c index 0eeda7e502db..2ac59564ded1 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c +++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c @@ -926,11 +926,11 @@ static void ionic_dim_update(struct ionic_qcq *qcq, int napi_mode) } dim_update_sample(qcq->cq.bound_intr->rearm_count, pkts, bytes, &dim_sample); - net_dim(&qcq->dim, dim_sample); + net_dim(&qcq->dim, &dim_sample); } int ionic_tx_napi(struct napi_struct *napi, int budget) { struct ionic_qcq *qcq = napi_to_qcq(napi); diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 792e9eadbfc3..869586c17ffd 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -2802,11 +2802,11 @@ static void virtnet_rx_dim_update(struct virtnet_info *vi, struct receive_queue dim_update_sample(rq->calls, u64_stats_read(&rq->stats.packets), u64_stats_read(&rq->stats.bytes), &cur_sample); - net_dim(&rq->dim, cur_sample); + net_dim(&rq->dim, &cur_sample); rq->packets_in_napi = 0; } static int virtnet_poll(struct napi_struct *napi, int budget) { diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c index b811446e0fa5..0b60ed16297c 100644 --- a/drivers/soc/fsl/dpio/dpio-service.c +++ b/drivers/soc/fsl/dpio/dpio-service.c @@ -889,10 +889,10 @@ void dpaa2_io_update_net_dim(struct dpaa2_io *d, __u64 frames, __u64 bytes) d->bytes += bytes; d->frames += frames; dim_update_sample(d->event_ctr, d->frames, d->bytes, &dim_sample); - net_dim(&d->rx_dim, dim_sample); + net_dim(&d->rx_dim, &dim_sample); spin_unlock(&d->dim_lock); } EXPORT_SYMBOL(dpaa2_io_update_net_dim); diff --git a/include/linux/dim.h b/include/linux/dim.h index 84579a50ae7f..06543fd40fcc 100644 --- a/include/linux/dim.h +++ b/include/linux/dim.h @@ -423,11 +423,11 @@ struct dim_cq_moder net_dim_get_def_tx_moderation(u8 cq_period_mode); * * Called by the consumer. * This is the main logic of the algorithm, where data is processed in order * to decide on next required action. */ -void net_dim(struct dim *dim, struct dim_sample end_sample); +void net_dim(struct dim *dim, const struct dim_sample *end_sample); /* RDMA DIM */ /* * RDMA DIM profile: diff --git a/lib/dim/net_dim.c b/lib/dim/net_dim.c index d7e7028e9b19..d6aa09a979b3 100644 --- a/lib/dim/net_dim.c +++ b/lib/dim/net_dim.c @@ -345,33 +345,33 @@ static bool net_dim_decision(struct dim_stats *curr_stats, struct dim *dim) dim->prev_stats = *curr_stats; return dim->profile_ix != prev_ix; } -void net_dim(struct dim *dim, struct dim_sample end_sample) +void net_dim(struct dim *dim, const struct dim_sample *end_sample) { struct dim_stats curr_stats; u16 nevents; switch (dim->state) { case DIM_MEASURE_IN_PROGRESS: nevents = BIT_GAP(BITS_PER_TYPE(u16), - end_sample.event_ctr, + end_sample->event_ctr, dim->start_sample.event_ctr); if (nevents < DIM_NEVENTS) break; - if (!dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats)) + if (!dim_calc_stats(&dim->start_sample, end_sample, &curr_stats)) break; if (net_dim_decision(&curr_stats, dim)) { dim->state = DIM_APPLY_NEW_PROFILE; schedule_work(&dim->work); break; } fallthrough; case DIM_START_MEASURE: - dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr, - end_sample.byte_ctr, &dim->start_sample); + dim_update_sample(end_sample->event_ctr, end_sample->pkt_ctr, + end_sample->byte_ctr, &dim->start_sample); dim->state = DIM_MEASURE_IN_PROGRESS; break; case DIM_APPLY_NEW_PROFILE: break; }
net_dim() is currently passed a struct dim_sample argument by value. struct dim_sample is 24 bytes. Since this is greater 16 bytes, x86-64 passes it on the stack. All callers have already initialized dim_sample on the stack, so passing it by value requires pushing a duplicated copy to the stack. Either witing to the stack and immediately reading it, or perhaps dereferencing addresses relative to the stack pointer in a chain of push instructions, seems to perform quite poorly. In a heavy TCP workload, mlx5e_handle_rx_dim() consumes 3% of CPU time, 94% of which is attributed to the first push instruction to copy dim_sample on the stack for the call to net_dim(): // Call ktime_get() 0.26 |4ead2: call 4ead7 <mlx5e_handle_rx_dim+0x47> // Pass the address of struct dim in %rdi |4ead7: lea 0x3d0(%rbx),%rdi // Set dim_sample.pkt_ctr |4eade: mov %r13d,0x8(%rsp) // Set dim_sample.byte_ctr |4eae3: mov %r12d,0xc(%rsp) // Set dim_sample.event_ctr 0.15 |4eae8: mov %bp,0x10(%rsp) // Duplicate dim_sample on the stack 94.16 |4eaed: push 0x10(%rsp) 2.79 |4eaf1: push 0x10(%rsp) 0.07 |4eaf5: push %rax // Call net_dim() 0.21 |4eaf6: call 4eafb <mlx5e_handle_rx_dim+0x6b> To allow the caller to reuse the struct dim_sample already on the stack, pass the struct dim_sample by reference to net_dim(). Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> --- Documentation/networking/net_dim.rst | 2 +- drivers/net/ethernet/amazon/ena/ena_netdev.c | 2 +- drivers/net/ethernet/broadcom/bcmsysport.c | 2 +- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++-- drivers/net/ethernet/broadcom/genet/bcmgenet.c | 2 +- drivers/net/ethernet/freescale/enetc/enetc.c | 2 +- drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 4 ++-- drivers/net/ethernet/intel/ice/ice_txrx.c | 4 ++-- drivers/net/ethernet/intel/idpf/idpf_txrx.c | 4 ++-- drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 2 +- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++-- drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c | 4 ++-- drivers/net/ethernet/netronome/nfp/nfd3/dp.c | 4 ++-- drivers/net/ethernet/netronome/nfp/nfdk/dp.c | 4 ++-- drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 2 +- drivers/net/virtio_net.c | 2 +- drivers/soc/fsl/dpio/dpio-service.c | 2 +- include/linux/dim.h | 2 +- lib/dim/net_dim.c | 10 +++++----- 19 files changed, 31 insertions(+), 31 deletions(-)