| Message ID | 20230712125455.1986455-9-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | blk-mq: fix wrong queue mapping for kdump kernel | expand |
On Wed, Jul 12, 2023 at 2:55 PM Ming Lei <ming.lei@redhat.com> wrote: > > Take blk-mq's knowledge into account for calculating io queues. > > Fix wrong queue mapping in case of kdump kernel. > > On arm and ppc64, 'maxcpus=1' is passed to kdump kernel command line, > see `Documentation/admin-guide/kdump/kdump.rst`, so num_possible_cpus() > still returns all CPUs because 'maxcpus=1' just bring up one single > cpu core during booting. > > blk-mq sees single queue in kdump kernel, and in driver's viewpoint > there are still multiple queues, this inconsistency causes driver to apply > wrong queue mapping for handling IO, and IO timeout is triggered. > > Meantime, single queue makes much less resource utilization, and reduce > risk of kernel failure. > > Cc: Jack Wang <jinpu.wang@cloud.ionos.com> > Signed-off-by: Ming Lei <ming.lei@redhat.com> Acked-by: Jack Wang <jinpu.wang@ionos.com> thx! > --- > drivers/scsi/pm8001/pm8001_init.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c > index 2e886c1d867d..e2416f556560 100644 > --- a/drivers/scsi/pm8001/pm8001_init.c > +++ b/drivers/scsi/pm8001/pm8001_init.c > @@ -965,6 +965,8 @@ static u32 pm8001_setup_msix(struct pm8001_hba_info *pm8001_ha) > rc = pci_alloc_irq_vectors(pm8001_ha->pdev, 1, 1, > PCI_IRQ_MSIX); > } else { > + unsigned int max_vecs = min_t(unsigned int, PM8001_MAX_MSIX_VEC, > + blk_mq_max_nr_hw_queues() + 1); > /* > * Queue index #0 is used always for housekeeping, so don't > * include in the affinity spreading. > @@ -973,7 +975,7 @@ static u32 pm8001_setup_msix(struct pm8001_hba_info *pm8001_ha) > .pre_vectors = 1, > }; > rc = pci_alloc_irq_vectors_affinity( > - pm8001_ha->pdev, 2, PM8001_MAX_MSIX_VEC, > + pm8001_ha->pdev, 2, max_vecs, > PCI_IRQ_MSIX | PCI_IRQ_AFFINITY, &desc); > } > > -- > 2.40.1 >
diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c index 2e886c1d867d..e2416f556560 100644 --- a/drivers/scsi/pm8001/pm8001_init.c +++ b/drivers/scsi/pm8001/pm8001_init.c @@ -965,6 +965,8 @@ static u32 pm8001_setup_msix(struct pm8001_hba_info *pm8001_ha) rc = pci_alloc_irq_vectors(pm8001_ha->pdev, 1, 1, PCI_IRQ_MSIX); } else { + unsigned int max_vecs = min_t(unsigned int, PM8001_MAX_MSIX_VEC, + blk_mq_max_nr_hw_queues() + 1); /* * Queue index #0 is used always for housekeeping, so don't * include in the affinity spreading. @@ -973,7 +975,7 @@ static u32 pm8001_setup_msix(struct pm8001_hba_info *pm8001_ha) .pre_vectors = 1, }; rc = pci_alloc_irq_vectors_affinity( - pm8001_ha->pdev, 2, PM8001_MAX_MSIX_VEC, + pm8001_ha->pdev, 2, max_vecs, PCI_IRQ_MSIX | PCI_IRQ_AFFINITY, &desc); }
Take blk-mq's knowledge into account for calculating io queues. Fix wrong queue mapping in case of kdump kernel. On arm and ppc64, 'maxcpus=1' is passed to kdump kernel command line, see `Documentation/admin-guide/kdump/kdump.rst`, so num_possible_cpus() still returns all CPUs because 'maxcpus=1' just bring up one single cpu core during booting. blk-mq sees single queue in kdump kernel, and in driver's viewpoint there are still multiple queues, this inconsistency causes driver to apply wrong queue mapping for handling IO, and IO timeout is triggered. Meantime, single queue makes much less resource utilization, and reduce risk of kernel failure. Cc: Jack Wang <jinpu.wang@cloud.ionos.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/scsi/pm8001/pm8001_init.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)