The driver is using irq_poll() (a NAPI like generic interface) for completing individual I/O requests. This could be replaced with threaded interrupts. The threaded interrupt runs as a RT thread with priority 50-FIFO. It should run as the first task after the interrupt unless a task with higher priority is active. It can be interrupt by another hardware interrupt or a softirq. This has been compile tested only. I'm interested if it causes any regressions, improves the situation or neither. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> --- REPOST of https://https://lkml.kernel.org/r/.kernel.org/all/20211029074902.4fayed6mcltifgdz@xxxxxxxxxxxxx/ v1…v2: - Properly initialize variables in be_isr_misx_th() as reported by the bot. drivers/scsi/be2iscsi/Kconfig | 1 - drivers/scsi/be2iscsi/be.h | 3 +- drivers/scsi/be2iscsi/be_iscsi.c | 8 +- drivers/scsi/be2iscsi/be_main.c | 146 ++++++++++++++----------------- drivers/scsi/be2iscsi/be_main.h | 2 +- 5 files changed, 75 insertions(+), 85 deletions(-) diff --git a/drivers/scsi/be2iscsi/Kconfig b/drivers/scsi/be2iscsi/Kconfig index 958c9b46ec787..0118b2a765caf 100644 --- a/drivers/scsi/be2iscsi/Kconfig +++ b/drivers/scsi/be2iscsi/Kconfig @@ -4,7 +4,6 @@ config BE2ISCSI depends on PCI && SCSI && NET select SCSI_ISCSI_ATTRS select ISCSI_BOOT_SYSFS - select IRQ_POLL help This driver implements the iSCSI functionality for Emulex diff --git a/drivers/scsi/be2iscsi/be.h b/drivers/scsi/be2iscsi/be.h index 4c58a02590c7b..8623886810310 100644 --- a/drivers/scsi/be2iscsi/be.h +++ b/drivers/scsi/be2iscsi/be.h @@ -12,7 +12,7 @@ #include <linux/pci.h> #include <linux/if_vlan.h> -#include <linux/irq_poll.h> + #define FW_VER_LEN 32 #define MCC_Q_LEN 128 #define MCC_CQ_LEN 256 @@ -90,7 +90,6 @@ struct be_eq_obj { struct beiscsi_hba *phba; struct be_queue_info *cq; struct work_struct mcc_work; /* Work Item */ - struct irq_poll iopoll; }; struct be_mcc_obj { diff --git a/drivers/scsi/be2iscsi/be_iscsi.c b/drivers/scsi/be2iscsi/be_iscsi.c index 8aeaddc93b167..e15d5c7ef611e 100644 --- a/drivers/scsi/be2iscsi/be_iscsi.c +++ b/drivers/scsi/be2iscsi/be_iscsi.c @@ -1224,15 +1224,17 @@ static void beiscsi_flush_cq(struct beiscsi_hba *phba) struct be_eq_obj *pbe_eq; struct hwi_controller *phwi_ctrlr; struct hwi_context_memory *phwi_context; + struct pci_dev *pcidev; phwi_ctrlr = phba->phwi_ctrlr; phwi_context = phwi_ctrlr->phwi_ctxt; + pcidev = phba->pcidev; for (i = 0; i < phba->num_cpus; i++) { pbe_eq = &phwi_context->be_eq[i]; - irq_poll_disable(&pbe_eq->iopoll); - beiscsi_process_cq(pbe_eq, BE2_MAX_NUM_CQ_PROC); - irq_poll_enable(&pbe_eq->iopoll); + disable_irq(pci_irq_vector(pcidev, i)); + beiscsi_process_cq(pbe_eq); + enable_irq(pci_irq_vector(pcidev, i)); } } diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c index ab55681145f8a..4dc4b840a17dc 100644 --- a/drivers/scsi/be2iscsi/be_main.c +++ b/drivers/scsi/be2iscsi/be_main.c @@ -35,7 +35,6 @@ #include <linux/iscsi_boot_sysfs.h> #include <linux/module.h> #include <linux/bsg-lib.h> -#include <linux/irq_poll.h> #include <scsi/libiscsi.h> #include <scsi/scsi_bsg_iscsi.h> @@ -51,7 +50,6 @@ #include "be_mgmt.h" #include "be_cmds.h" -static unsigned int be_iopoll_budget = 10; static unsigned int be_max_phys_size = 64; static unsigned int enable_msix = 1; @@ -59,7 +57,6 @@ MODULE_DESCRIPTION(DRV_DESC " " BUILD_STR); MODULE_VERSION(BUILD_STR); MODULE_AUTHOR("Emulex Corporation"); MODULE_LICENSE("GPL"); -module_param(be_iopoll_budget, int, 0); module_param(enable_msix, int, 0); module_param(be_max_phys_size, uint, S_IRUGO); MODULE_PARM_DESC(be_max_phys_size, @@ -699,6 +696,48 @@ static irqreturn_t be_isr_mcc(int irq, void *dev_id) return IRQ_HANDLED; } +static irqreturn_t be_iopoll(struct be_eq_obj *pbe_eq) +{ + struct beiscsi_hba *phba; + unsigned int ret, io_events; + struct be_eq_entry *eqe = NULL; + struct be_queue_info *eq; + + phba = pbe_eq->phba; + if (beiscsi_hba_in_error(phba)) + return IRQ_NONE; + + io_events = 0; + eq = &pbe_eq->q; + eqe = queue_tail_node(eq); + while (eqe->dw[offsetof(struct amap_eq_entry, valid) / 32] & + EQE_VALID_MASK) { + AMAP_SET_BITS(struct amap_eq_entry, valid, eqe, 0); + queue_tail_inc(eq); + eqe = queue_tail_node(eq); + io_events++; + } + hwi_ring_eq_db(phba, eq->id, 1, io_events, 0, 1); + + ret = beiscsi_process_cq(pbe_eq); + pbe_eq->cq_count += ret; + beiscsi_log(phba, KERN_INFO, + BEISCSI_LOG_CONFIG | BEISCSI_LOG_IO, + "BM_%d : rearm pbe_eq->q.id =%d ret %d\n", + pbe_eq->q.id, ret); + if (!beiscsi_hba_in_error(phba)) + hwi_ring_eq_db(phba, pbe_eq->q.id, 0, 0, 1, 1); + + return IRQ_HANDLED; +} + +static irqreturn_t be_isr_misx_th(int irq, void *dev_id) +{ + struct be_eq_obj *pbe_eq = dev_id; + + return be_iopoll(pbe_eq); +} + /** * be_isr_msix - The isr routine of the driver. * @irq: Not used @@ -716,9 +755,22 @@ static irqreturn_t be_isr_msix(int irq, void *dev_id) phba = pbe_eq->phba; /* disable interrupt till iopoll completes */ hwi_ring_eq_db(phba, eq->id, 1, 0, 0, 1); - irq_poll_sched(&pbe_eq->iopoll); - return IRQ_HANDLED; + return IRQ_WAKE_THREAD; +} + +static irqreturn_t be_isr_thread(int irq, void *dev_id) +{ + struct beiscsi_hba *phba; + struct hwi_controller *phwi_ctrlr; + struct hwi_context_memory *phwi_context; + struct be_eq_obj *pbe_eq; + + phba = dev_id; + phwi_ctrlr = phba->phwi_ctrlr; + phwi_context = phwi_ctrlr->phwi_ctxt; + pbe_eq = &phwi_context->be_eq[0]; + return be_iopoll(pbe_eq); } /** @@ -738,6 +790,7 @@ static irqreturn_t be_isr(int irq, void *dev_id) struct be_ctrl_info *ctrl; struct be_eq_obj *pbe_eq; int isr, rearm; + irqreturn_t ret; phba = dev_id; ctrl = &phba->ctrl; @@ -777,10 +830,11 @@ static irqreturn_t be_isr(int irq, void *dev_id) /* rearm for MCCQ */ rearm = 1; } + ret = IRQ_HANDLED; if (io_events) - irq_poll_sched(&pbe_eq->iopoll); + ret = IRQ_WAKE_THREAD; hwi_ring_eq_db(phba, eq->id, 0, (io_events + mcc_events), rearm, 1); - return IRQ_HANDLED; + return ret; } static void beiscsi_free_irqs(struct beiscsi_hba *phba) @@ -822,9 +876,10 @@ static int beiscsi_init_irqs(struct beiscsi_hba *phba) goto free_msix_irqs; } - ret = request_irq(pci_irq_vector(pcidev, i), - be_isr_msix, 0, phba->msi_name[i], - &phwi_context->be_eq[i]); + ret = request_threaded_irq(pci_irq_vector(pcidev, i), + be_isr_msix, be_isr_misx_th, + 0, phba->msi_name[i], + &phwi_context->be_eq[i]); if (ret) { beiscsi_log(phba, KERN_ERR, BEISCSI_LOG_INIT, "BM_%d : %s-Failed to register msix for i = %d\n", @@ -850,8 +905,8 @@ static int beiscsi_init_irqs(struct beiscsi_hba *phba) } } else { - ret = request_irq(pcidev->irq, be_isr, IRQF_SHARED, - "beiscsi", phba); + ret = request_threaded_irq(pcidev->irq, be_isr, be_isr_thread, + IRQF_SHARED, "beiscsi", phba); if (ret) { beiscsi_log(phba, KERN_ERR, BEISCSI_LOG_INIT, "BM_%d : %s-Failed to register irq\n", @@ -1842,12 +1897,11 @@ static void beiscsi_mcc_work(struct work_struct *work) /** * beiscsi_process_cq()- Process the Completion Queue * @pbe_eq: Event Q on which the Completion has come - * @budget: Max number of events to processed * * return * Number of Completion Entries processed. **/ -unsigned int beiscsi_process_cq(struct be_eq_obj *pbe_eq, int budget) +unsigned int beiscsi_process_cq(struct be_eq_obj *pbe_eq) { struct be_queue_info *cq; struct sol_cqe *sol; @@ -2021,55 +2075,12 @@ unsigned int beiscsi_process_cq(struct be_eq_obj *pbe_eq, int budget) queue_tail_inc(cq); sol = queue_tail_node(cq); num_processed++; - if (total == budget) - break; } hwi_ring_cq_db(phba, cq->id, num_processed, 1); return total; } -static int be_iopoll(struct irq_poll *iop, int budget) -{ - unsigned int ret, io_events; - struct beiscsi_hba *phba; - struct be_eq_obj *pbe_eq; - struct be_eq_entry *eqe = NULL; - struct be_queue_info *eq; - - pbe_eq = container_of(iop, struct be_eq_obj, iopoll); - phba = pbe_eq->phba; - if (beiscsi_hba_in_error(phba)) { - irq_poll_complete(iop); - return 0; - } - - io_events = 0; - eq = &pbe_eq->q; - eqe = queue_tail_node(eq); - while (eqe->dw[offsetof(struct amap_eq_entry, valid) / 32] & - EQE_VALID_MASK) { - AMAP_SET_BITS(struct amap_eq_entry, valid, eqe, 0); - queue_tail_inc(eq); - eqe = queue_tail_node(eq); - io_events++; - } - hwi_ring_eq_db(phba, eq->id, 1, io_events, 0, 1); - - ret = beiscsi_process_cq(pbe_eq, budget); - pbe_eq->cq_count += ret; - if (ret < budget) { - irq_poll_complete(iop); - beiscsi_log(phba, KERN_INFO, - BEISCSI_LOG_CONFIG | BEISCSI_LOG_IO, - "BM_%d : rearm pbe_eq->q.id =%d ret %d\n", - pbe_eq->q.id, ret); - if (!beiscsi_hba_in_error(phba)) - hwi_ring_eq_db(phba, pbe_eq->q.id, 0, 0, 1, 1); - } - return ret; -} - static void hwi_write_sgl_v2(struct iscsi_wrb *pwrb, struct scatterlist *sg, unsigned int num_sg, struct beiscsi_io_task *io_task) @@ -5311,10 +5322,6 @@ static int beiscsi_enable_port(struct beiscsi_hba *phba) phwi_ctrlr = phba->phwi_ctrlr; phwi_context = phwi_ctrlr->phwi_ctxt; - for (i = 0; i < phba->num_cpus; i++) { - pbe_eq = &phwi_context->be_eq[i]; - irq_poll_init(&pbe_eq->iopoll, be_iopoll_budget, be_iopoll); - } i = (phba->pcidev->msix_enabled) ? i : 0; /* Work item for MCC handling */ @@ -5347,10 +5354,6 @@ static int beiscsi_enable_port(struct beiscsi_hba *phba) return 0; cleanup_port: - for (i = 0; i < phba->num_cpus; i++) { - pbe_eq = &phwi_context->be_eq[i]; - irq_poll_disable(&pbe_eq->iopoll); - } hwi_cleanup_port(phba); disable_msix: @@ -5382,10 +5385,6 @@ static void beiscsi_disable_port(struct beiscsi_hba *phba, int unload) beiscsi_free_irqs(phba); pci_free_irq_vectors(phba->pcidev); - for (i = 0; i < phba->num_cpus; i++) { - pbe_eq = &phwi_context->be_eq[i]; - irq_poll_disable(&pbe_eq->iopoll); - } cancel_delayed_work_sync(&phba->eqd_update); cancel_work_sync(&phba->boot_work); /* WQ might be running cancel queued mcc_work if we are not exiting */ @@ -5640,11 +5639,6 @@ static int beiscsi_dev_probe(struct pci_dev *pcidev, phwi_ctrlr = phba->phwi_ctrlr; phwi_context = phwi_ctrlr->phwi_ctxt; - for (i = 0; i < phba->num_cpus; i++) { - pbe_eq = &phwi_context->be_eq[i]; - irq_poll_init(&pbe_eq->iopoll, be_iopoll_budget, be_iopoll); - } - i = (phba->pcidev->msix_enabled) ? i : 0; /* Work item for MCC handling */ pbe_eq = &phwi_context->be_eq[i]; @@ -5701,10 +5695,6 @@ static int beiscsi_dev_probe(struct pci_dev *pcidev, hwi_disable_intr(phba); beiscsi_free_irqs(phba); disable_iopoll: - for (i = 0; i < phba->num_cpus; i++) { - pbe_eq = &phwi_context->be_eq[i]; - irq_poll_disable(&pbe_eq->iopoll); - } destroy_workqueue(phba->wq); free_twq: hwi_cleanup_port(phba); diff --git a/drivers/scsi/be2iscsi/be_main.h b/drivers/scsi/be2iscsi/be_main.h index 98977c0700f1a..5c0e54eaf9e99 100644 --- a/drivers/scsi/be2iscsi/be_main.h +++ b/drivers/scsi/be2iscsi/be_main.h @@ -799,7 +799,7 @@ void hwi_ring_cq_db(struct beiscsi_hba *phba, unsigned int id, unsigned int num_processed, unsigned char rearm); -unsigned int beiscsi_process_cq(struct be_eq_obj *pbe_eq, int budget); +unsigned int beiscsi_process_cq(struct be_eq_obj *pbe_eq); void beiscsi_process_mcc_cq(struct beiscsi_hba *phba); struct pdu_nop_out { -- 2.34.1
