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.
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
v1…v2:
- Properly initialize variables in be_isr_misx_th() as reported by the
bot.
- Drop jitendra.bhivare@xxxxxxxxxxxx and
subbu.seetharaman@xxxxxxxxxxxx from Cc:, the email bounces.
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 e70f69f791db6..ef09e298cca94 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,
@@ -696,6 +693,48 @@ 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
@@ -713,9 +752,22 @@ 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);
}
/**
@@ -735,6 +787,7 @@ 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;
@@ -774,10 +827,11 @@ 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)
@@ -819,9 +873,10 @@ 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",
@@ -847,8 +902,8 @@ 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",
@@ -1839,12 +1894,11 @@ 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;
@@ -2018,55 +2072,12 @@ 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)
@@ -5308,10 +5319,6 @@ 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 */
@@ -5344,10 +5351,6 @@ 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:
@@ -5379,10 +5382,6 @@ 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 */
@@ -5637,11 +5636,6 @@ 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];
@@ -5698,10 +5692,6 @@ 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 {
--
2.33.1
