| Message ID | 20230712125455.1986455-5-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | blk-mq: fix wrong queue mapping for kdump kernel | expand |
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c index 20e1607c6282..bbec11220286 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c @@ -2550,6 +2550,9 @@ static int interrupt_preinit_v3_hw(struct hisi_hba *hisi_hba) hisi_hba->cq_nvecs = vectors - BASE_VECTORS_V3_HW - hisi_hba->iopoll_q_cnt; + if (hisi_hba->cq_nvecs > blk_mq_max_nr_hw_queues()) + hisi_hba->cq_nvecs = blk_mq_max_nr_hw_queues(); + shost->nr_hw_queues = hisi_hba->cq_nvecs + hisi_hba->iopoll_q_cnt; return devm_add_action(&pdev->dev, hisi_sas_v3_free_vectors, pdev);
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: Xiang Chen <chenxiang66@hisilicon.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 3 +++ 1 file changed, 3 insertions(+)