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igb: when number of CPUs > 4 combine tx/rx queues to allow more queues
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This patch makes it so that nics such as 82576 and newer can support more
hardware queues when there are more than 4 cpus by combining a tx/rx queue
pair onto one interrupt so that 8 queue pairs can be supported and thus
allow for more queues.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Alexander Duyck authored and David S. Miller committed Nov 14, 2009
1 parent 115f459 commit a99955f
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Showing 2 changed files with 27 additions and 13 deletions.
9 changes: 5 additions & 4 deletions drivers/net/igb/igb.h
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Original file line number Diff line number Diff line change
Expand Up @@ -59,10 +59,10 @@ struct igb_adapter;
#define MAX_Q_VECTORS 8

/* Transmit and receive queues */
#define IGB_MAX_RX_QUEUES (adapter->vfs_allocated_count ? \
(adapter->vfs_allocated_count > 6 ? 1 : 2) : 4)
#define IGB_MAX_TX_QUEUES IGB_MAX_RX_QUEUES
#define IGB_ABS_MAX_TX_QUEUES 4
#define IGB_MAX_RX_QUEUES (adapter->vfs_allocated_count ? 2 : \
(hw->mac.type > e1000_82575 ? 8 : 4))
#define IGB_ABS_MAX_TX_QUEUES 8
#define IGB_MAX_TX_QUEUES IGB_MAX_RX_QUEUES

#define IGB_MAX_VF_MC_ENTRIES 30
#define IGB_MAX_VF_FUNCTIONS 8
Expand Down Expand Up @@ -315,6 +315,7 @@ struct igb_adapter {
u16 rx_ring_count;
unsigned int vfs_allocated_count;
struct vf_data_storage *vf_data;
u32 rss_queues;
};

#define IGB_FLAG_HAS_MSI (1 << 0)
Expand Down
31 changes: 22 additions & 9 deletions drivers/net/igb/igb_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -296,10 +296,10 @@ static void igb_cache_ring_register(struct igb_adapter *adapter)
* and continue consuming queues in the same sequence
*/
if (adapter->vfs_allocated_count) {
for (; i < adapter->num_rx_queues; i++)
for (; i < adapter->rss_queues; i++)
adapter->rx_ring[i].reg_idx = rbase_offset +
Q_IDX_82576(i);
for (; j < adapter->num_tx_queues; j++)
for (; j < adapter->rss_queues; j++)
adapter->tx_ring[j].reg_idx = rbase_offset +
Q_IDX_82576(j);
}
Expand Down Expand Up @@ -618,14 +618,15 @@ static void igb_set_interrupt_capability(struct igb_adapter *adapter)
int numvecs, i;

/* Number of supported queues. */
adapter->num_rx_queues = min_t(u32, IGB_MAX_RX_QUEUES, num_online_cpus());
adapter->num_tx_queues = min_t(u32, IGB_MAX_TX_QUEUES, num_online_cpus());
adapter->num_rx_queues = adapter->rss_queues;
adapter->num_tx_queues = adapter->rss_queues;

/* start with one vector for every rx queue */
numvecs = adapter->num_rx_queues;

/* if tx handler is seperate add 1 for every tx queue */
numvecs += adapter->num_tx_queues;
if (!(adapter->flags & IGB_FLAG_QUEUE_PAIRS))
numvecs += adapter->num_tx_queues;

/* store the number of vectors reserved for queues */
adapter->num_q_vectors = numvecs;
Expand Down Expand Up @@ -666,6 +667,7 @@ static void igb_set_interrupt_capability(struct igb_adapter *adapter)
}
#endif
adapter->vfs_allocated_count = 0;
adapter->rss_queues = 1;
adapter->flags |= IGB_FLAG_QUEUE_PAIRS;
adapter->num_rx_queues = 1;
adapter->num_tx_queues = 1;
Expand Down Expand Up @@ -1824,6 +1826,17 @@ static int __devinit igb_sw_init(struct igb_adapter *adapter)
adapter->vfs_allocated_count = max_vfs;

#endif /* CONFIG_PCI_IOV */
adapter->rss_queues = min_t(u32, IGB_MAX_RX_QUEUES, num_online_cpus());

/*
* if rss_queues > 4 or vfs are going to be allocated with rss_queues
* then we should combine the queues into a queue pair in order to
* conserve interrupts due to limited supply
*/
if ((adapter->rss_queues > 4) ||
((adapter->rss_queues > 1) && (adapter->vfs_allocated_count > 6)))
adapter->flags |= IGB_FLAG_QUEUE_PAIRS;

/* This call may decrease the number of queues */
if (igb_init_interrupt_scheme(adapter)) {
dev_err(&pdev->dev, "Unable to allocate memory for queues\n");
Expand Down Expand Up @@ -2015,7 +2028,7 @@ static int igb_setup_all_tx_resources(struct igb_adapter *adapter)
}
}

for (i = 0; i < IGB_MAX_TX_QUEUES; i++) {
for (i = 0; i < IGB_ABS_MAX_TX_QUEUES; i++) {
int r_idx = i % adapter->num_tx_queues;
adapter->multi_tx_table[i] = &adapter->tx_ring[r_idx];
}
Expand Down Expand Up @@ -2199,7 +2212,7 @@ static void igb_setup_mrqc(struct igb_adapter *adapter)
array_wr32(E1000_RSSRK(0), j, rsskey);
}

num_rx_queues = adapter->num_rx_queues;
num_rx_queues = adapter->rss_queues;

if (adapter->vfs_allocated_count) {
/* 82575 and 82576 supports 2 RSS queues for VMDq */
Expand Down Expand Up @@ -2255,7 +2268,7 @@ static void igb_setup_mrqc(struct igb_adapter *adapter)
E1000_VT_CTL_DEFAULT_POOL_SHIFT;
wr32(E1000_VT_CTL, vtctl);
}
if (adapter->num_rx_queues > 1)
if (adapter->rss_queues > 1)
mrqc = E1000_MRQC_ENABLE_VMDQ_RSS_2Q;
else
mrqc = E1000_MRQC_ENABLE_VMDQ;
Expand Down Expand Up @@ -2385,7 +2398,7 @@ static inline void igb_set_vmolr(struct igb_adapter *adapter, int vfn)
/* clear all bits that might not be set */
vmolr &= ~(E1000_VMOLR_BAM | E1000_VMOLR_RSSE);

if (adapter->num_rx_queues > 1 && vfn == adapter->vfs_allocated_count)
if (adapter->rss_queues > 1 && vfn == adapter->vfs_allocated_count)
vmolr |= E1000_VMOLR_RSSE; /* enable RSS */
/*
* for VMDq only allow the VFs and pool 0 to accept broadcast and
Expand Down

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