| Message ID | 20241031002326.3426181-2-csander@purestorage.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [resend,1/2] dim: make dim_calc_stats() inputs const pointers | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
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
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(-)