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ixgbe: determine vector count inside ixgbe_acquire_msix_vectors 

Our calculated v_budget doesn't matter except if we allocate MSI-X
vectors. We shouldn't need to calculate this outside of the function, so
don't. Instead, only calculate it once we attempt to acquire MSI-X
vectors. This helps collocate all of the MSI-X vector code together.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Jacob Keller 2014-09-03 08:12:57 +00:00 committed by Jeff Kirsher
parent 027bb561ef
commit 3bcf344657
1 changed files with 37 additions and 37 deletions
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74
drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
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@ -696,23 +696,45 @@ static void ixgbe_set_num_queues(struct ixgbe_adapter *adapter)
ixgbe_set_rss_queues(adapter);
}
static int ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter,
int vectors)
/**
* ixgbe_acquire_msix_vectors - acquire MSI-X vectors
* @adapter: board private structure
*
* Attempts to acquire a suitable range of MSI-X vector interrupts. Will
* return a negative error code if unable to acquire MSI-X vectors for any
* reason.
*/
static int ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter)
{
int i, vector_threshold;
struct ixgbe_hw *hw = &adapter->hw;
int i, vectors, vector_threshold;
/* We'll want at least 2 (vector_threshold):
* 1) TxQ[0] + RxQ[0] handler
* 2) Other (Link Status Change, etc.)
/* We start by asking for one vector per queue pair */
vectors = max(adapter->num_rx_queues, adapter->num_tx_queues);
/* It is easy to be greedy for MSI-X vectors. However, it really
* doesn't do much good if we have a lot more vectors than CPUs. We'll
* be somewhat conservative and only ask for (roughly) the same number
* of vectors as there are CPUs.
*/
vectors = min_t(int, vectors, num_online_cpus());
/* Some vectors are necessary for non-queue interrupts */
vectors += NON_Q_VECTORS;
/* Hardware can only support a maximum of hw.mac->max_msix_vectors.
* With features such as RSS and VMDq, we can easily surpass the
* number of Rx and Tx descriptor queues supported by our device.
* Thus, we cap the maximum in the rare cases where the CPU count also
* exceeds our vector limit
*/
vectors = min_t(int, vectors, hw->mac.max_msix_vectors);
/* We want a minimum of two MSI-X vectors for (1) a TxQ[0] + RxQ[0]
* handler, and (2) an Other (Link Status Change, etc.) handler.
*/
vector_threshold = MIN_MSIX_COUNT;
/*
* The more we get, the more we will assign to Tx/Rx Cleanup
* for the separate queues...where Rx Cleanup >= Tx Cleanup.
* Right now, we simply care about how many we'll get; we'll
* set them up later while requesting irq's.
*/
adapter->msix_entries = kcalloc(vectors,
sizeof(struct msix_entry),
GFP_KERNEL);
@ -1069,32 +1091,10 @@ static void ixgbe_reset_interrupt_capability(struct ixgbe_adapter *adapter)
**/
static void ixgbe_set_interrupt_capability(struct ixgbe_adapter *adapter)
{
struct ixgbe_hw *hw = &adapter->hw;
int v_budget, err;
int err;
/*
* It's easy to be greedy for MSI-X vectors, but it really
* doesn't do us much good if we have a lot more vectors
* than CPU's. So let's be conservative and only ask for
* (roughly) the same number of vectors as there are CPU's.
* The default is to use pairs of vectors.
*/
v_budget = max(adapter->num_rx_queues, adapter->num_tx_queues);
v_budget = min_t(int, v_budget, num_online_cpus());
v_budget += NON_Q_VECTORS;
/*
* At the same time, hardware can only support a maximum of
* hw.mac->max_msix_vectors vectors. With features
* such as RSS and VMDq, we can easily surpass the number of Rx and Tx
* descriptor queues supported by our device. Thus, we cap it off in
* those rare cases where the cpu count also exceeds our vector limit.
*/
v_budget = min_t(int, v_budget, hw->mac.max_msix_vectors);
/* A failure in MSI-X entry allocation isn't fatal, but it does
* mean we disable MSI-X capabilities of the adapter. */
if (!ixgbe_acquire_msix_vectors(adapter, v_budget))
/* We will try to get MSI-X interrupts first */
if (!ixgbe_acquire_msix_vectors(adapter))
return;
/* At this point, we do not have MSI-X capabilities. We need to