The execution time for page fault request handling is performance critical and needs to be monitored. This adds code to sample the execution time of page fault request handling.
Signed-off-by: Lu Baolu <baolu...@linux.intel.com> Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu...@linux.intel.com --- drivers/iommu/intel/svm.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index d3d028c6a727..6bff9a7f9133 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -24,6 +24,7 @@ #include <trace/events/intel_iommu.h> #include "pasid.h" +#include "perf.h" #include "../iommu-sva-lib.h" static irqreturn_t prq_event_thread(int irq, void *d); @@ -838,8 +839,8 @@ static int prq_to_iommu_prot(struct page_req_dsc *req) return prot; } -static int -intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc) +static int intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev, + struct page_req_dsc *desc) { struct iommu_fault_event event; @@ -871,6 +872,12 @@ intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc) event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA; memcpy(event.fault.prm.private_data, desc->priv_data, sizeof(desc->priv_data)); + } else if (dmar_latency_enabled(iommu, DMAR_LATENCY_PRQ)) { + /* + * If the private data fields are not used by hardware, use it + * to monitor the prq handle latency. + */ + event.fault.prm.private_data[0] = ktime_to_ns(ktime_get()); } return iommu_report_device_fault(dev, &event); @@ -983,7 +990,7 @@ static irqreturn_t prq_event_thread(int irq, void *d) * If prq is to be handled outside iommu driver via receiver of * the fault notifiers, we skip the page response here. */ - if (intel_svm_prq_report(sdev->dev, req)) + if (intel_svm_prq_report(iommu, sdev->dev, req)) handle_bad_prq_event(iommu, req, QI_RESP_INVALID); trace_prq_report(iommu, sdev->dev, req->qw_0, req->qw_1, @@ -1172,6 +1179,9 @@ int intel_svm_page_response(struct device *dev, if (private_present) memcpy(&desc.qw2, prm->private_data, sizeof(prm->private_data)); + else if (prm->private_data[0]) + dmar_latency_update(iommu, DMAR_LATENCY_PRQ, + ktime_to_ns(ktime_get()) - prm->private_data[0]); qi_submit_sync(iommu, &desc, 1, 0); } -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
