The prev_pkt field in ice_txq_stats is used by ice_check_for_hung_subtask as a way to detect potential Tx hangs due to missed interrupts.
The value is based on the packet count, but its an int and not really a "statistic". The value is signed so that we can use -1 as a "no work pending" value. A following change is going to refactor the stats to all use the u64_stat_t type and accessor functions. Leaving prev_pkt as the lone int feels a bit strange. Instead, move it out of ice_txq_stats and place it in the ice_tx_ring. We have 8 bytes still available in the 3rd cacheline, so this move saves a small amount of memory. It also shouldn't impact the Tx path heavily since its only accessed during initialization and the hang subtask. Reviewed-by: Aleksandr Loktionov <[email protected]> Signed-off-by: Jacob Keller <[email protected]> --- drivers/net/ethernet/intel/ice/ice_txrx.h | 3 ++- drivers/net/ethernet/intel/ice/ice_main.c | 6 +++--- drivers/net/ethernet/intel/ice/ice_txrx.c | 2 +- 3 files changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h index 78fed538ea0f..aa0b74e45bba 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.h +++ b/drivers/net/ethernet/intel/ice/ice_txrx.h @@ -138,7 +138,6 @@ struct ice_txq_stats { u64 restart_q; u64 tx_busy; u64 tx_linearize; - int prev_pkt; /* negative if no pending Tx descriptors */ }; struct ice_rxq_stats { @@ -354,6 +353,8 @@ struct ice_tx_ring { u32 txq_teid; /* Added Tx queue TEID */ + int prev_pkt; /* negative if no pending Tx descriptors */ + #define ICE_TX_FLAGS_RING_XDP BIT(0) #define ICE_TX_FLAGS_RING_VLAN_L2TAG1 BIT(1) #define ICE_TX_FLAGS_RING_VLAN_L2TAG2 BIT(2) diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c index 645a2113e8aa..df5da7b4ec62 100644 --- a/drivers/net/ethernet/intel/ice/ice_main.c +++ b/drivers/net/ethernet/intel/ice/ice_main.c @@ -160,7 +160,7 @@ static void ice_check_for_hang_subtask(struct ice_pf *pf) * pending work. */ packets = ring_stats->stats.pkts & INT_MAX; - if (ring_stats->tx_stats.prev_pkt == packets) { + if (tx_ring->prev_pkt == packets) { /* Trigger sw interrupt to revive the queue */ ice_trigger_sw_intr(hw, tx_ring->q_vector); continue; @@ -170,8 +170,8 @@ static void ice_check_for_hang_subtask(struct ice_pf *pf) * to ice_get_tx_pending() */ smp_rmb(); - ring_stats->tx_stats.prev_pkt = - ice_get_tx_pending(tx_ring) ? packets : -1; + tx_ring->prev_pkt = + ice_get_tx_pending(tx_ring) ? packets : -1; } } } diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index ad76768a4232..30073ed9ca99 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -499,7 +499,7 @@ int ice_setup_tx_ring(struct ice_tx_ring *tx_ring) tx_ring->next_to_use = 0; tx_ring->next_to_clean = 0; - tx_ring->ring_stats->tx_stats.prev_pkt = -1; + tx_ring->prev_pkt = -1; return 0; err: -- 2.51.0.rc1.197.g6d975e95c9d7
