| Message ID | 20190213105041.13537-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | genirq/affinity: add .calc_sets for improving IRQ allocation & spread | expand |
On 2/13/19 3:50 AM, Ming Lei wrote: > Hi, > > Currently pre-caculated set vectors are provided by driver for > allocating & spread vectors. This way only works when drivers passes > same 'max_vecs' and 'min_vecs' to pci_alloc_irq_vectors_affinity(), > also requires driver to retry the allocating & spread. > > As Bjorn and Keith mentioned, the current usage & interface for irq sets > is a bit awkward because the retrying should have been avoided by providing > one resonable 'min_vecs'. However, if 'min_vecs' isn't same with > 'max_vecs', number of the allocated vectors is unknown before calling > pci_alloc_irq_vectors_affinity(), then each set's vectors can't be > pre-caculated. > > Add a new callback of .calc_sets into 'struct irq_affinity' so that > driver can caculate set vectors after IRQ vector is allocated and > before spread IRQ vectors. Much improved, thanks for doing this work. You can add Reviewed-by: Jens Axboe <axboe@kernel.dk> if you want.
Hi, Currently pre-caculated set vectors are provided by driver for allocating & spread vectors. This way only works when drivers passes same 'max_vecs' and 'min_vecs' to pci_alloc_irq_vectors_affinity(), also requires driver to retry the allocating & spread. As Bjorn and Keith mentioned, the current usage & interface for irq sets is a bit awkward because the retrying should have been avoided by providing one resonable 'min_vecs'. However, if 'min_vecs' isn't same with 'max_vecs', number of the allocated vectors is unknown before calling pci_alloc_irq_vectors_affinity(), then each set's vectors can't be pre-caculated. Add a new callback of .calc_sets into 'struct irq_affinity' so that driver can caculate set vectors after IRQ vector is allocated and before spread IRQ vectors. V3: - don't mark 'affd' as const in related functions - add sanity check on affd->nr_sets - remove the local variable of 'nr_sets' in irq_create_affinity_masks - set .nr_sets as 2 in nvme - update comment in msi.c V2: - add .calc_sets instead of .setup_affinity() which is easy to be abused by drivers Ming Lei (5): genirq/affinity: don't mark 'affd' as const genirq/affinity: store irq set vectors in 'struct irq_affinity' genirq/affinity: add new callback for caculating set vectors nvme-pci: avoid irq allocation retrying via .calc_sets genirq/affinity: Document .calc_sets as required in case of multiple sets drivers/nvme/host/pci.c | 63 ++++++++++++----------------------------------- drivers/pci/msi.c | 34 ++++++++++++++----------- include/linux/interrupt.h | 13 +++++++--- include/linux/pci.h | 4 +-- kernel/irq/affinity.c | 26 ++++++++++++------- 5 files changed, 64 insertions(+), 76 deletions(-)