| Message ID | 75788c5da384b16633fdab43d37a277aa92f38fd.1382103786.git.agordeev@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
> Subject: [PATCH RFC v2 29/29] vmxnet3: Make use of pcim_enable_msix_range() interface ... > diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c > index d33802c..e552d2b 100644 > --- a/drivers/net/vmxnet3/vmxnet3_drv.c > +++ b/drivers/net/vmxnet3/vmxnet3_drv.c > @@ -2735,39 +2735,19 @@ vmxnet3_read_mac_addr(struct vmxnet3_adapter *adapter, u8 *mac) > */ > > static int > -vmxnet3_acquire_msix_vectors(struct vmxnet3_adapter *adapter, > - int vectors) > +vmxnet3_acquire_msix_vectors(struct vmxnet3_adapter *adapter, int vectors) > { > - int err = -EINVAL, vector_threshold; > - vector_threshold = VMXNET3_LINUX_MIN_MSIX_VECT; > - > - while (vectors >= vector_threshold) { > - err = pci_enable_msix(adapter->pdev, adapter->intr.msix_entries, > - vectors); > - if (!err) { > - adapter->intr.num_intrs = vectors; > - return 0; > - } else if (err < 0) { > - dev_err(&adapter->netdev->dev, > - "Failed to enable MSI-X, error: %d\n", err); > - return err; > - } else if (err < vector_threshold) { > - dev_info(&adapter->pdev->dev, > - "Number of MSI-Xs which can be allocated " > - "is lower than min threshold required.\n"); > - return -ENOSPC; > - } else { > - /* If fails to enable required number of MSI-x vectors > - * try enabling minimum number of vectors required. > - */ > - dev_err(&adapter->netdev->dev, > - "Failed to enable %d MSI-X, trying %d instead\n", > - vectors, vector_threshold); > - vectors = vector_threshold; > - } > + vectors = pcim_enable_msix_range(adapter->pdev, > + adapter->intr.msix_entries, vectors, > + VMXNET3_LINUX_MIN_MSIX_VECT); > + if (vectors < 0) { > + dev_err(&adapter->netdev->dev, > + "Failed to enable MSI-X, error: %d\n", vectors); > + return vectors; > } > > - return err; > + adapter->intr.num_intrs = vectors; > + return 0; > } AFAICT the old code either used the requested number or the minimum number. The new code seems to claim an intermediate number of interrupts - but probably only uses the minimum number. This wastes the last few MSI-X interrupts. The code (especially the calling code) would be easier to read if the 'vectors' value wasn't explicitly passed. David -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Oct 21, 2013 at 09:51:32AM +0100, David Laight wrote: > > Subject: [PATCH RFC v2 29/29] vmxnet3: Make use of pcim_enable_msix_range() interface > AFAICT the old code either used the requested number or the minimum number. > The new code seems to claim an intermediate number of interrupts - but probably > only uses the minimum number. Yes, you are right. I missed the vectors = vector_threshold assignment. This driver is inapplicable as an example.
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index d33802c..e552d2b 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -2735,39 +2735,19 @@ vmxnet3_read_mac_addr(struct vmxnet3_adapter *adapter, u8 *mac) */ static int -vmxnet3_acquire_msix_vectors(struct vmxnet3_adapter *adapter, - int vectors) +vmxnet3_acquire_msix_vectors(struct vmxnet3_adapter *adapter, int vectors) { - int err = -EINVAL, vector_threshold; - vector_threshold = VMXNET3_LINUX_MIN_MSIX_VECT; - - while (vectors >= vector_threshold) { - err = pci_enable_msix(adapter->pdev, adapter->intr.msix_entries, - vectors); - if (!err) { - adapter->intr.num_intrs = vectors; - return 0; - } else if (err < 0) { - dev_err(&adapter->netdev->dev, - "Failed to enable MSI-X, error: %d\n", err); - return err; - } else if (err < vector_threshold) { - dev_info(&adapter->pdev->dev, - "Number of MSI-Xs which can be allocated " - "is lower than min threshold required.\n"); - return -ENOSPC; - } else { - /* If fails to enable required number of MSI-x vectors - * try enabling minimum number of vectors required. - */ - dev_err(&adapter->netdev->dev, - "Failed to enable %d MSI-X, trying %d instead\n", - vectors, vector_threshold); - vectors = vector_threshold; - } + vectors = pcim_enable_msix_range(adapter->pdev, + adapter->intr.msix_entries, vectors, + VMXNET3_LINUX_MIN_MSIX_VECT); + if (vectors < 0) { + dev_err(&adapter->netdev->dev, + "Failed to enable MSI-X, error: %d\n", vectors); + return vectors; } - return err; + adapter->intr.num_intrs = vectors; + return 0; }
Signed-off-by: Alexander Gordeev <agordeev@redhat.com> --- drivers/net/vmxnet3/vmxnet3_drv.c | 40 +++++++++--------------------------- 1 files changed, 10 insertions(+), 30 deletions(-)