From: Dean Luick <dean.lu...@intel.com>
When under heavy load, the send handler can run too long without allowing other
tasks to run. Add a conditional resched to break this up.
Reviewed-by: Mike Marciniszyn <mike.marcinis...@intel.com>
Signed-off-by: Dean Luick <dean.lu...@intel.com>
Signed-off-by: Ira Weiny <ira.we...@intel.com>
---
drivers/staging/rdma/hfi1/chip.c | 10 ++++++++++
drivers/staging/rdma/hfi1/chip.h | 1 +
drivers/staging/rdma/hfi1/ruc.c | 12 ++++++++++++
drivers/staging/rdma/hfi1/verbs.h | 1 +
4 files changed, 24 insertions(+)
diff --git a/drivers/staging/rdma/hfi1/chip.c b/drivers/staging/rdma/hfi1/chip.c
index aad25b6686ff..1a6dd877c8d8 100644
--- a/drivers/staging/rdma/hfi1/chip.c
+++ b/drivers/staging/rdma/hfi1/chip.c
@@ -1530,6 +1530,14 @@ static u64 access_sw_kmem_wait(const struct cntr_entry
*entry,
return dd->verbs_dev.n_kmem_wait;
}
+static u64 access_sw_send_schedule(const struct cntr_entry *entry,
+ void *context, int vl, int mode, u64 data)
+{
+ struct hfi1_devdata *dd = (struct hfi1_devdata *)context;
+
+ return dd->verbs_dev.n_send_schedule;
+}
+
#define def_access_sw_cpu(cntr) \
static u64 access_sw_cpu_##cntr(const struct cntr_entry *entry,
\
void *context, int vl, int mode, u64 data) \
@@ -1720,6 +1728,8 @@ static struct cntr_entry dev_cntrs[DEV_CNTR_LAST] = {
access_sw_pio_wait),
[C_SW_KMEM_WAIT] = CNTR_ELEM("KmemWait", 0, 0, CNTR_NORMAL,
access_sw_kmem_wait),
+[C_SW_SEND_SCHED] = CNTR_ELEM("SendSched", 0, 0, CNTR_NORMAL,
+ access_sw_send_schedule),
};
static struct cntr_entry port_cntrs[PORT_CNTR_LAST] = {
diff --git a/drivers/staging/rdma/hfi1/chip.h b/drivers/staging/rdma/hfi1/chip.h
index 497c5de23d53..ebf9041a1c5e 100644
--- a/drivers/staging/rdma/hfi1/chip.h
+++ b/drivers/staging/rdma/hfi1/chip.h
@@ -787,6 +787,7 @@ enum {
C_SW_VTX_WAIT,
C_SW_PIO_WAIT,
C_SW_KMEM_WAIT,
+ C_SW_SEND_SCHED,
DEV_CNTR_LAST /* Must be kept last */
};
diff --git a/drivers/staging/rdma/hfi1/ruc.c b/drivers/staging/rdma/hfi1/ruc.c
index faad1b93703e..8614b070545c 100644
--- a/drivers/staging/rdma/hfi1/ruc.c
+++ b/drivers/staging/rdma/hfi1/ruc.c
@@ -820,6 +820,9 @@ void hfi1_make_ruc_header(struct hfi1_qp *qp, struct
hfi1_other_headers *ohdr,
ohdr->bth[2] = cpu_to_be32(bth2);
}
+/* when sending, force a reschedule every one of these periods */
+#define SEND_RESCHED_TIMEOUT (5 * HZ) /* 5s in jiffies */
+
/**
* hfi1_do_send - perform a send on a QP
* @work: contains a pointer to the QP
@@ -836,6 +839,7 @@ void hfi1_do_send(struct work_struct *work)
struct hfi1_pportdata *ppd = ppd_from_ibp(ibp);
int (*make_req)(struct hfi1_qp *qp);
unsigned long flags;
+ unsigned long timeout;
if ((qp->ibqp.qp_type == IB_QPT_RC ||
qp->ibqp.qp_type == IB_QPT_UC) &&
@@ -864,6 +868,7 @@ void hfi1_do_send(struct work_struct *work)
spin_unlock_irqrestore(&qp->s_lock, flags);
+ timeout = jiffies + SEND_RESCHED_TIMEOUT;
do {
/* Check for a constructed packet to be sent. */
if (qp->s_hdrwords != 0) {
@@ -877,6 +882,13 @@ void hfi1_do_send(struct work_struct *work)
/* Record that s_hdr is empty. */
qp->s_hdrwords = 0;
}
+
+ /* allow other tasks to run */
+ if (unlikely(time_after(jiffies, timeout))) {
+ cond_resched();
+ ppd->dd->verbs_dev.n_send_schedule++;
+ timeout = jiffies + SEND_RESCHED_TIMEOUT;
+ }
} while (make_req(qp));
}
diff --git a/drivers/staging/rdma/hfi1/verbs.h
b/drivers/staging/rdma/hfi1/verbs.h
index afaa0fe619fe..e4a8a0d4ccf8 100644
--- a/drivers/staging/rdma/hfi1/verbs.h
+++ b/drivers/staging/rdma/hfi1/verbs.h
@@ -754,6 +754,7 @@ struct hfi1_ibdev {
u64 n_piowait;
u64 n_txwait;
u64 n_kmem_wait;
+ u64 n_send_schedule;
u32 n_pds_allocated; /* number of PDs allocated for device */
spinlock_t n_pds_lock;
--
1.8.2
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