Re: [RFC net-next 05/14] Fix intel/ixgbevf
From: Eilon Greenstein <hidden>
Date: 2012-06-19 16:07:07
On Tue, 2012-06-19 at 08:39 -0700, Alexander Duyck wrote:
On 06/19/2012 08:13 AM, Yuval Mintz wrote:quoted
Signed-off-by: Yuval Mintz <redacted> Signed-off-by: Eilon Greenstein <redacted> Cc: Jeff Kirsher <redacted> --- drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index f69ec42..3ad46c2 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c@@ -2014,7 +2014,7 @@ err_tx_ring_allocation: static int ixgbevf_set_interrupt_capability(struct ixgbevf_adapter *adapter) { int err = 0; - int vector, v_budget; + int vector, v_budget, ncpu; /* * It's easy to be greedy for MSI-X vectors, but it really@@ -2022,8 +2022,9 @@ static int ixgbevf_set_interrupt_capability(struct ixgbevf_adapter *adapter) * than CPU's. So let's be conservative and only ask for * (roughly) twice the number of vectors as there are CPU's. */ + ncpu = min_t(int, num_online_cpus(), DEFAULT_MAX_NUM_RSS_QUEUES); v_budget = min(adapter->num_rx_queues + adapter->num_tx_queues, - (int)(num_online_cpus() * 2)) + NON_Q_VECTORS; + ncpu * 2) + NON_Q_VECTORS; /* A failure in MSI-X entry allocation isn't fatal, but it does * mean we disable MSI-X capabilities of the adapter. */This change is pointless on the ixgbevf driver. The VF hardware can support at most 4 RSS queues. As such num_rx_queues + num_tx_queues will never exceed 8 so you are essentially adding a necessary min(x,8).
It is pointless with the current value, but if someone will edit the kernel source code and replace the 8 with a 2, it will become meaningful. The compiler will optimize this part, and I think that for completion, it is best to keep this reference so a future default number change will not be missed. Eilon